Quote Originally Posted by ascanius View Post
I tried this out in gimp. It adds a whole lot of complicated. Depending on the rotation, I created divergent boundaries where I had none before. I kept this limited to only my largest plate but I realize that I have to be careful otherwise divergent boundaries would spring up all over the place.
Yep, I am struggling with the same thing. In some cases the best solution is to change the shape of the plate a little. In other cases I think that local "divergence" is covered by the movement of the adjacent plates and not necessarily liked to new crust formation. In other cases, if you want a more one-direction sort of movement, it's a matter of moving the Euler pole away from the plate.

About your question about Euler poles and rotation. Yes, you could do it with a compass on a flat surface (if the map was an ortographic projection centered on the rotation axis). I say this not being the mathematical expert, which I'm not, but the guy who has been fiddling and reading around. From my experience, different projections give totally different areas of crust creation and crust subduction around a plate.