1) Not supported in both MP and SP for obvious reasons including the fun of not knowing.
2) If you do add it, make it so that everyone can have it, no price, no qi, everyone must be equal, it's like the goddamn powerup thing.
3) I'm a replay maker and I'm not 10th dan if an option like this appeared even with all the disagreement I'd still like to have it and not be left out.