I think making the cabals straight forward good vs. evil, chaos vs. order is kinda bleh. Multi-faceted systems are more interesting anyways.

Mayby get rid of tribunal, and let empire take over guarding protected cities - perhaps with a twist.

Outlander is fairly interesting as an outlaw cabal.

Ragerrrrs are necessary, because it's an awesome diehard mentality and good for the game in general.

Goodie cabal I guess is necessary.

Right now, all the cabal choices are really, really great, and diversity is always fun, but I think limiting people to a fewer cabals would inevitably result in more group on group action, which in return results in more carrion for the fields.