The Higley hub is good. I have one and it turns true and is helpful in tail-heavy situations.

If you move the engine, then you will be changing the moments of the aircraft too. A model is designed to have the propeller at a certain location. Most guys don't realize that moving the engine changes the flight qualities of a model. The model will fly, but not as designed.

To answer your question in a concrete way, I think a .46 could fly a 12+ pound model if you had a long enough runway and it was lightly loaded (lots of wing).