As for the suspension - try pneumatic cylinders. Or add some torsion bars to that.
Is the front suspension working okay? The wishbones mounting points to the hub do not match with the turning axis of the hub.
What about putting 16 tooth gear on the same axle as 24 tooth gear on the bottom and use is to drive chain (use 16 tooth gears on top then). It would extend one stud to the front though.
Wonderful job, very agressive look, I love it.
Any chance for a video or more pictures? How did you manage to get the power distribution between axles?