I'm pretty sure what you're talking about is color separation aka "the rainbow effect" which is only a symptom of single chip DLP projectors that use color wheels. The Pioneer projector you're talking about is a 3 chip LCOS projector so you aren't going to have to worry about that at all.
As far as the 3D goes, the maximum input refresh rate accepted on that projector is 60hz. You may be able to force something higher but chances are that's as good as it gets. For 3D you want higher refresh rates. Preferably something at or above 120hz. The reasoning behind that is to reduce image flicker. With active 3D glasses the slower the panels on the glasses blank the more noticeable they are to your eyes and it gives the impression that the image is flickering. So when you do 30hz per eye per second (to achieve 60hz on the Pioneer) you may be able to see a "flickering" image. That's really the only drawback with doing 3D at 60hz.
And by the way "light corners" are exactly what they sound like. It's only really noticeable on a completely black frame. Some, or all, of the corners seem to be brighter than the center of the screen. As of late most projectors don't suffer from that issue.