I think its a good idea, but the issue of balance comes into play. It's hard to try and add all these moves and abilities while keeping the players somewhat equal, ya know? I'll suggest it in the next meeting though.
Been suggested before, like r4 says, then they wouldnt be able to hold the beans. Plus in the show cell and piccolo could really only regenerate limbs, Buu on the other hand can regenerate pretty much whatever the hell he wants. Its fine how it is