So in other words, you're using a mac... There is a mac version of BrawlBox out there... But I heard it does not works as well, and it's a clone of one of the older versions...
1: Yes it is possible. In Peach's case, her Side Smash weapons are actually part of the Peach Model, and is changed using Model Events in PSA. But some weapons are Articles, and have a separate Model to them. Also called with PSA.
2: Yes, you can have very different looks for different Character Colors. Each Recolor is its own PAC file.
3: Ask somebody who knows about modeling for I am clueless in this area...
Username: A Bloody Canadian Type of hacks you make: PSA, Anything Texture Related, 2D Stages, BRSTMs, Animations Type of hack you'd like to recieve: PSA or Character Model Hack... Your favorite Video Game: Resonance of Fate/End of Eternity, Kingdom Hearts, Jet Set Radio Future Your favorite Anime: Another