Alessi
All of Alessi's normal moves will hit you normally, with the exception of 2C which will only hit you at about half of its normal range. His 63214 special in normal mode will wiff you, as it travels along the ground.
A big problem for Alessi is his lack of effective anti-airs. The best one probably being 214AA which can be easy to bait out by faking an approach via midair and then punishing him with a 214AA of your own. If he hasn't got meter he's fucked. Alessi can't really do shit vs a flying petshop if your movement is good enough. Respect his gun though, avoid flying into it like a dumbass. Move around the target and approach him, if he realises he's fucked and tries to put the gun away, you still have 33 frames (like half a second) to punish him for bringing it out in the first place. As for Alessi in the air, he doesn't have many options to take you out as all his air moves can be beaten out by 665C. Not a matchup you should struggle with.
Avdol
Avdol would be a tougher matchup for you if his 2A didn't miss against you. He has tools (stand mode 6A, DP) to take you out of the air at any height, and pokes (2C, stand mode A) that are incredibly long, combined with powerful projectile supers to take you down.
Avdol is a very strong opponent in the air, with high priority air-to-airs capable of keeping you out and the ability to double and even triple jump to match your height. Avdol is not an opponent I would recommend flying much against. Most Avdols will know this and attempt to approach you by jumping.
This is a matchup where playing defensively and letting Avdol come to you can be beneficial as your opponent is able to wall you out and block off a lot of your approaches. Avoid letting him get a lifelead and stay away from him while using icicles defensively as it is very hard for Avdol to effectively open you up. A lot of your damage in this matchup will come from stray hits and anti-airs, but if you manage to get a combo against him it's basically game-over for Avdol. Eventually you will run into that guy who believes they're entitled to use the ankh invincibility glitch against you because you picked petshop. To counter this, you can bait them into going for an ankh by dashing in with icicles up but instead flying over in an attempt to cross them up. If timed successfully you may be able to trick them into doing 214AA and wasting a bar of meter, from there it's just a matter of trying to rush them down and pressure them before they get that bar back. Although you'll probably find that most players bad enough to try to use an invincibility glitch on you will eventually end up misinputting their s.623AA as s.236AA anyway as they try to mash out their iframes.
Black Polnareff
A lot of BPol's stuff isn't gonna hit you. This also happens to be stuff that is important to BPol. Good for you! His 2A jab can hit you at full range but for the most part that's the only low you'll have to worry about and you should be able to see his dashing 2C coming. His rekka and main loop will whiff against you standing so he doesn't have his "high damage" against you. You won't struggle much against BPol whether you try to rush down or try to lame him out. Watch out for his 214AA, if it's blocked or whiffs you can get some pretty high damage punishes against it, keep in mind you can punish it on hit in the corner too.
Chaka
Chaka's primary hit confirm starts with a low (2A) move in either mode, neither of which hit you so you're already at a bit of an advantage. Due to chaka's amazing guard cancel your blockstrings won't be of much use as if Chaka can land a GC into combo on you, you can kiss goodbye to a good chunk of your health. For Chaka I'd recommend trying to get him to approach you. Play defensively and set up your icicles to hit him if he tries to get in or take any opportunity to hit him with a UB and get some good damage from there. Chaka's great air control can take you out of flight and his supers are capable of shutting down some of your other approaches so be aware of these risks while trying to get in.
Devo
Devo does hilariously bad against you. He literally can't hit you low. It's actually tragic. If you can block and hold A and B you will have no trouble at all dealing with Devo. Keep your C button free so you can tech grabs and anti-air him as grabs and j.C chip will be the only damage he can really go for on you. If you attempt to rush Devo down, be wary of his 214AA as it has a lot of iframes and devo can get around 40% of your health from using it as a reversal against you. Also note that to land your combos on Devo while crouching, you will need to start with a 662A 5C link rather than 665C otherwise you will fly over him.
Dio
None of Dio's moves whiff against you, which means he can do his combos normally and thus is capable of getting a lot of damage on you. Dio isn't too threatening in the air and doesn't have much to take you down without using meter, although only around two of his knives will hit you flying and you can attempt to super-iframe through his road roller. A lot of Dio's pressure comes from his blockstrings, which holding your icicles while blocking will negate. If you can land an icicle on him and combo from it he's pretty much done for. Avoid using 5S and 41236S in an attempt to zone him out, as he will be able to punish it with his teleport or just beat them out with knives.
Hol Horse
Hol's 2C sweep will not it you, leaving him with less options to knock you down and perform his okizeme. This matchup is basically just Hol doing his best to mildly annoy and bore you before he dies. Flying isn't terribly safe against Hol as he can take you out of the air with his projectiles or a super. Keep in mind too that his 236C and low 236AA will both hit you. If you read a raw 236AA you can punish it by either flying over it or crouching below the standing version and using 2S. Your goal in this matchup is to get right up in Hol's face and beat the shit out of him. Build icicles as you approach him so you'll have a UB ready to go, and once you are close keep the pressure up, just watch out for his projectiles and supers.
Hoingo
While Boingo loses Hol's powerful anti-flying supers, he does gain a much better S bullet. A good Hoingo player can use this to take you out of the air and shut down your dash-ins with ease so be careful. Same as Hol, his 236C and low 236AA still hit you, so watch out for projectiles as you approach. When you get close, do your best to keep him under pressure and if he gets the chance to roll, make sure you grab him or attempt to get in mid air to avoid being slammed in the face by a 360 command grab. Despite his command grab, Hoingo is not much of a threat at close range and will go down with ease just like Hol if you're able to pressure him and get into a combo.
Iggy
Iggy has very little that he can do in s.off. Most of his attacks will miss so he's not gonna be a problem. Just like crouching Devo, you will have to start your combos with a 662A 5C link on stand off Iggy to make sure it will connect. Your raging birdie hitgrab will also whiff unless you hold [2] during it's active frames.
In s.on Iggy doesn't do much better. If anything he's putting himself at more of a risk as he can now be hit by 2 icicles at once. Take care against s.on Iggy, he suffers pretty badly against you but if he gets the opportunity a combo can take around 40% of your health. Combo confirms shouldn't come hard, just wait until you can smack a blocked attack or charge with an icicle or until you get the opportunity for a UB. If iggy attempts to fly, poke him with your projectiles from afar to get him down.
Oldseph
Oldseph is another character who really lacks many options. Oldseph doesn't have much to take out of midair. Flying is going to be pretty safe against him, it'll probably be your best option to get in and avoid getting hit. Once you manage to fly in and get through his defence with a UB setup you'll be able to hit him with a combo that'll either take away most of his health or outright kill him.
Jotaro
Jotaro is a solid contender who can give Petshop a run for his money. *ALL* of Jotaro's attacks, including his low moves, can hit Petshop as if he weren't even floating. Although his star finger okizeme won't hit you in time. In s.off Jotaro will rely a lot on blockstrings and pressure, which you can deal with by using your A and B icicles on block with C free to tech grabs, same way you'd handle Dio. Jotaro doesn't have a whole lot he can do to take you out of the air in s.off either.
In stand on, flying becomes much riskier due to Jotaro's quick jabs, good air moves, and double jumps. You're better off trying to keep him at mid range and backing up until you can get icicles up before attempting to hit with a 662A or a 2S, just watch out for his tandem and star breaker iframes when you go to UB him.
Kakyoin
Kakyoin's claim to fame is his safe gameplay using his nets, in addition to his 50/50 okizeme game also using his nets. He can not hit you with his 2A, 3B or 463214+C wrap, but all of his other moves remain unaffected. Rushing Kak down will be your best option, take advantage of your flight and 3C in some cases to get around his nets and pressure him until you can open him up and land a combo. Keep in mind if Kak tries to zone you out, his s.236X is punishable by your 214AA. If his stand gauge is low, you can even attempt to throw out a 214AA to stand crash him if he blocks it and get rid of any nets he currently has up. Just be careful with nets, avoiding them is hard but it is possible. If you get hit by one at least try to make sure you're being hit in midair to avoid dying from a net loop into 99+ hit tandem.
Khan
The 2a he depends on heavily whiffs on you standing, and if you're crouching you're busy setting up icicles anyway and have him where you want him. He has Nkak's s.off health without any upsides really. This won't last long, he can't do anything to your aerial pokes or zoning him out, this is *laughably* bad for khan, the threat of him countering any of your moves or landing double 5C into charge C is negligible.
Mariah
You can either completely rush down and break through Mariah's defence with relative ease or beat her at her own game by out-zoning her with icicles, 5S and 41236S. Her tracking 236X can take you out of the air, but as long as you haven't been hit by sockets (which you really shouldn't be) you can punish her specials with your supers at lower levels.
Midler
Midler can't hit with 2A, 3B and 2C in normal mode, limiting her combo and poking options. She can, however, hit you low with 4B. As such, she'll probably try to zone you with cars and harpoons, both of which will not hit you at max height meaning flying in is relatively safe. Be forewarned that her motor show 50/50 game will work on Petshop as well as anybody else, and will do quite a bit of damage.
Stay close if possible, as she has the least options there with the majority of her comboable normal moves unable to hit.
New Kakyoin
New Kakyoin loses Kakyoin's ability to place nets in normal mode and his nets now have a launch property making them less useful. Otherwise, the game plays out similarly. His 2A, 3B and 214+A/B/C wrap will whiff. Keep close to him and watch out for his s.on pokes and nets and you shouldn't have much problem as long as you are the one in control of the pressure. Watch out for NKak's solid guard cancel against your blockstrings and his strong mixup game if he manages to switch the pressure on you. Make sure that you don't get knocked down, as his 50/50 net oki is even better with his stand on dashes.
Petshop
A key thing to be aware of against petshop is that while your 2A and 2S will whiff, dashing 2B and 2C will still hit low meaning you can still hit him with lows that you can combo off for high damage. Avoid doing 2S in combos against petshop out of habit too. Holding A and B on block is especially valuable in this matchup as much as it is in any matchup where your opponent relies a lot on blockstrings and pressure, as usual keep your C button open to grab the opponent or tech a grab. Flying against another Petshop can be risky due to his ability to take you down with a 214AA or even just an icicle if you're in the wrong spot.
Polnareff
While Polnareff's s.off 2B and 2C whiff, there are ways for him to adapt his combos to still connect against you, the one you will most likely see is starting with j.B so be aware of that. Polnareff has some great anti-airs and pretty good high priority air-to-airs too making flying a risky game. Avoid letting him get shooting star out. A lot of Polnareff Players will think they're sneaky by trying to buffer the charge during roundstart but you can shut them down by catching them off guard with a 214B. Keep him around mid-range until you think you have a good opportunity to set up an unblockable, like Jotaro however watch out for tandem reversals or another super, as Pol is more dangerous in this regard as his meter build is much better.
Rubber Soul
Rubber Soul's 2A can hit you, but his Rubber Wrap can not. Rubber can still decently pressure you and rush you down, so be careful. Your anti-airs aren't the best for dealing with his j.S and Rubber's strong air-to-airs and anti-airs will take you out of the sky without much problem. Take special care not to eat his counter special, as the super that will follow it is especially damaging on Petshop. If you manage to get away from Rubber, he will likely go for a 236AA at fullscreen for some chip, which is important to stay aware of and know how to roll through it. The key to winning is just keeping the pressure on him and not letting up while watching out for counters, which you can counter with a hitgrab such as 2S or AA6BC or even just by dunking an icicle on his head if you have one.
Shadow Dio
Shadow Dio's 2A can hit you, and as such, all of his normal combos and most of his pressure functions normally. Sdio benefits from being able to keep you out by beating out just about all of your normals with his, both on the ground and in air. Icicles will carry you especially in this matchup. Avoid taking hits at all costs, as his 5C will be used a lot to beat out your approaches and will do a lot of damage as well as allow him to link into combos for even further damage and knock you down, where he can hit you with his wide selection of dangerous okizeme options. Also keep in mind that SDio's book works on projectiles, including your icicles, and he has enough time to punish your 5S and 41236S on reaction. The best way to go about this matchup is to keep Sdio at mid-long range until you can set up icicles to approach and stay out of midair unless you have icicles nearby to beat out any of his attacks.
Vanilla Ice
Another strong opponent, Vanilla Ice is generally a dominant character, however, his inability to hit you with his normal mode 2A severely limits his options. Without being able to use 2A, Vanilla is probably going to try playing against you in stand mode. Keep yourself safe with projectiles and icicles before seizing an opportunity to get in, as Vanilla's stand pokes will beat most of your combo starters.
If Vanilla starts using the orbs, an overhead super or two should serve to intimidate him into using a new strategy.
Do not fly against Vanilla Ice. His airborne mobility (thanks to his double jump and multiple air dashes) is nearly as good as yours. He's faster horizontally, but much slower vertically. His IADs won't be nearly as safe due to your icicles. If you can make him block a move of yours while he's in mid air such as 41236S or icicles, you can keep him away from you until he either lands and becomes vulnerable once again to your combos, or takes the hit and attempts to tech away.
Young Joseph
Young Joseph is another character who doesn't have much he can do against you. You can bully him from the air, by rushing in on the ground, and punish most of his important tools (eg: his 214S is punishable by your 214AA, 236AA, and 3C 1/2/3S). Just like Khan there isn't a lot he can do against you, just watch out for 236AA and you'll be more than fine.
