Purple can work if you are good at masking combos and are a master at camera movement yawing drags etc. As for Red its counters and dfa interrupt spam is about the best you will get out of it atm. Currently Red and Purple aren't very competitive styles compared to yellow and blue so just have...
MBII would greatly benefit from a sound revamp. But as Mace said, the devs don't really have the resources or anyone with enough experience/dedication in the matter to do such a thing yet. So an unofficial sound mod sounds like the way to go.