Yeah, if you ever get to a critical burst situation with Tina, you are basically boned. Either
a) Hold mid punch, get thrown for 100+ points of damage + whatever the stun combo was
b) Don't hold mid punch, get critical bursted, take another 40 points after the launch.
Add in her unholdable stuns and she's actually pretty monstrous as a combo character on top of her throw damage.
The thing is, Tina has to get the stun started, and if you're in her face that's very difficult for her. Fast mids are very hard to deal with since she either has to try to jab you out or hold/sidestep them. You have to be careful of going high or low predictably as she has great crushes for those (1p and 4k), but rushdown is really hard to deal with especially online since so much becomes safe. Helena is a nightmare since she can basically never stop doing strings since she never has to really worry about throw punishment.
Bayman is a different beast, he's much more evasive and defensively capable. Tina can butcher you if you make one big mistake; Bayman will pick you apart over two or three smaller errors, but he's got better tools to force those errors. I'm not as competent with him, but he's fishing for any time he's got enough frame advantage to throw an OH out and if he ever launches you it'll be 80 or 90 points guaranteed with the ground throw, and he's always going to be trying to push to a wall if there is one. If he gets you to the wall, it's a very bad day for you. You have to be more careful rushing him down since he's got the tank rolls/parries/advanced holds to get him out of trouble if he needs.
Bass, I don't know nearly enough about to give great advice, except obviously if he knocks you down and picks you up you just have to guess duck or standing block, basically. 41236f+p beats one and 33p beats the other and I think either gives him reset options. He's slower than Tina, though, so you can probably rush him down too.