For your stationary turning issues, I'd like to point you to this thread:
http://www.chiefdelphi.com/forums/sh...hlight=current
Note the posts by Dave Lavery on the total current available to the servos. It's only 1 amp

. When you're stationary, you have evidence that your servos have trouble manipulating the steering. I'd be weary about this, as the mechanical stresses combined with current pull could be the cause of servos burning out. I'd have plenty of spares if I were you.
Also, I'd recommend putting some sort of support going from the main drive base to right next to the front wheels, or enclose the whole front. At the moment, a high speed off-centered frontal crash will knock your steering out of alignment, regardless of where you mount a front bumper to the current design.
Otherwise, this looks like a fantastic drive train!