Changes I would enjoy
Everyone's M-M string cancels into C.H
Gatlings exist (LLL to C.L works, LL to C.M works, pretty much higher levels of attacks can be canceled into if a lower level is used)
Hitstun bar above the enemy
Wall bounces
Guard Gauge
Specials (Little Fighter motion inputs, time to do D, F, L or even W, A, S, D, H)
Unique stages (next one better be a ring-out stage so you can test stage gimmicks!)