Active windows for A+K and B+K are like frame 1~20ish or so. The window is quite large but more importantly it isn't out in no man's land frame wise like SCV B+K or 4A+B. Just do it some time before you get hit and you'll be fine and it CAN interrupt a good deal of strings instead of near useless SCV aGI.
33B is a true mid except sometimes during step the characters would sway heavily and it COULD in situations hit high. The trade off is that it goes into his best over all Prep stance and can be done from an advancing 8wr.
Yup, 66A+B, basically trash since day one and it's going the distance in his moveset Rocky style.
Other things to note is that now Raph has a TON of moves that hit grounded.
A2A
1BB
1K
2K
BB
3B
FC3B
66A+B (I think)
3A+B
236A+B
Running slide of course
Prep A A
214 A
11A
1A
2A (yes, only sM 2A in the game that'll hit grounded IIRC)
FC2B
WSB
22B
I might have missed some, you get the point anyways.
Better yet, a couple of those are M instead of relying on 66B+K or 66A+B to hit M and grounded.