Since many of Nintendo's creations have multiple versions ([Mario, Dr. Mario, Baby Mario, etc...], [Link, Young Link, Toon Link, etc...], [etc...]), I think they should have you choose the characters, then give you a list of which version to play as, then let you choose a color. Now, I know that would take up a lot of space on the disc, but for something like that, I would easily be willing to toss the trophies or something. They kind of lost their flavor in Brawl anyway (for me, that is).
No trophies are the heart of Smash Bros. And no Baby Mario. How would that even work? But yes to bringing Dr. Mario and Young Link back. :yes: If used well, those were some of the fastest and most powerful characters in Melee...