I'd like to be able to select what 2 colors I can have associated with each of the mouse buttons at any given time. Right now, right click is always black.

Hmm. I've got other editors which do that, so I understand your need for the feature. However that's more than I wanted to bite off at this time (it would take some user interface changes).

I kinda liked the way it worked so that right button was always erase, but to each his own.