I just became aware of the modified PhysX plug-in:
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=384647#Post384647 which addresses these issues.
Thanks HeelX, rojart, Quad, and anyone else involved!

I hope these changes get moved into the official GS release soon

Joris Lambrecht
My Contributions: Relative Rotation, Window Sizing