4/5'd for some of the rules.
Some people like RPG have an amazing ability to combo, and they should be able to use that in tournaments. Capping combos to a certain number of skills doesn't allow for that. It seems like the TFT tourny's rules would work better for this (no more than 2x consecutive strings). This would prevent "cheap" infinites and still allow people to do long combos.
Combos should only count as a series of attack that are inescapable without skills. That way something like a ground AA hd AA hd AA would be legal (since it's entirely escapable) while Tia's slide AA slide AA slide AA would be illegal (can only escape using a skill with invincibility frames).