Her 214 stance is fine, I like the way 214{B} and 214B work in her stance options... But with 236{B} I have a radical change that could balance her out or possibly make her better... First 236{B}should be changed to 236B, getting rid of the hold command would make this attack more reliable and getting rid of the just frame means you don't have to worry about getting it in combos (even though I understand how easy it is to do) just remeber this is a nerf, somewhat... The properties of 236{B} should be changed to the just frame versions, which means on CH you get a launch and on normal hit you get a stun, but I believe that this attack shouldn't juggle anymore, so it would balance out the combo potential of this move with the difficulty in its execution... The new 236B should remain at i16 but only if its made safer to throw out, I would like it around -12 or -14 on grd (-12 doesn't sound bad), this move would become more reliable than 2B+K in this sense...
So the new 236B is the just frame version of 236{B}, but safer, and can't maintain it's rediculous juggling potential, so you're probably wondering about 236:B... The new 236:B will be the same as the original, but now the only way to execute it is by getting the just input... So it becomes more crucial to execute correctly for punishment... 236:B should be i14 all the time, and like senzait proposed, should be about -18 or less on grd... As punishment, I belive the damage should be increased, and on KND should hit them closer to Cass so she can get a tech mixup like she should in the first place...
My reasoning behind this, is I don't like the fact that the just versions of these attacks are meh, and rearranging the inputs and properties would make punishing with her a bit more solid... Now if you mess up 236:B for punishment, you have a semi-safe 236B to fall back on, which means you don't get in your damage (hey, you did mess up) but you do get a safe attack and some SCD to boot... 236:B will be able to punish all -14 on grd. attacks and deliver a tech trap mixup on wake-up... The new 236B can be used as a poke, and while hindering its combo potential in juggles, will simplify them, and reward Cass with a reliable combo starter... The properties of 214{B} and 214B should stay the same, but this time around I believe, 214B (fast hit) should be completly safe at around -10 on grd, so its a safe poke from her backstep however unlike the new 236:B, this version should hit them out of reach from her tech traps, or just not give any tech traps alltogether... 214{B} should be changed only so that it gives the same stun on hit and counter hit, this would make it a garaunteed followup to the 214 auto-GI, and give a combo opportunity for getting the GI... The new combo would be: 214{IMP}{B}, 236B, 66A+B, 4BB:A...