LMFAO @ Scorpion buffs. The character is fine right now. His mobility has huge variety in mind games, his KBs are almost too easy to access for a character of his archtype and his buttons aren't terrible. He should remain as-is until the meta evolves defensive option wise and see how it goes.
Having S1 as an anti-air is by design for some characters. Cetrion's S1 is crucial because her D2 is hilariously bad. Basically straight vertical hitbox making even KB uppercut punishes whiff, her recovery is so long you can take a trip to 7-11 buy a slurpee and maybe she's done recovering and without S1 we'd be borderline forced to use Natural Barrier which would make Komp Var #1 even more useless than it already is.
Hit boxes being modified? We've been dealing w/ janky hitboxes since UMK3 female ninjas (maybe even earlier, didn't play komp MK before that.) and that's part of the game.
I play Cetrion and even I know if there's no wave dash blocking she would become S tier. it's the only option for a lot of characters especially when the player respects Cetrion too much and is afraid to do something else to move in.
I think you're putting too much weight on breakaways. Yeah they're frustrating but now instead of 40 different defensive getup options they have they only have slow or normal getup which you can practice setups for. Some characters really excel because for 1 offense bar (in most cases) they have to burn both def. bars. Meaning one good setup and they eat that 1 off bar combo completely. I don't think it's terrible when you have chars like Sonya who w/ one string and meter does 32%+ and Scorpion can do 40% w/ KBs.
I'll address you point by point.
1: I want Scorpion to not have useless moves. I'd suggest quality of life improvements for everyone. I don't believe in having useless moves. Neither do the buffs I suggested have a thing to do with defensive options.
2: S1 anti air is definitely not by design especially since characters just have no anti air at all. They remove an aspect of the neutral, they eliminate jumping, eliminate setup diversity because I'm Sonya and I can just d1 under your cross up jump kick, it's toxic to the design of the game. Especially when the BEST WAY to get in on some of these characters would be to jump at a certain range where their neutral is weak.
3: Just because it was jank before doens't justify it. Stupid response.
4: Cetrion would only be S tier in a world where you're bad at walking someone down. Wave dashing eliminates neutral, especially since backwards movement is so gimped in comparison to it. You can't realistically play footsies and check people for moving WHICH IS PART OF NEUTRAL, because of the consistent block state.
5: If you watched Summit Of Time people always broke away and almost never bothered to use the defensive options. It's better because playing the wake up game puts YOU, the guy knocked down, into a higher state of variability because of the options. Things can snowball because you tried to roll or wake up, the breakaway situation reduces the amount of thinking both players have to do, which also means there's less risk for the guy who broke.