[Brando]

If his chassis is stiff enough (read: welded-in cage) there shouldn't be any flex when going over un-even road.

It will be fine with solid mounts. The torque tube is very sturdy, not weak by any means. If it can be used to absorb some of the torsional flex of the body all the better. To do any damage you would have to seriously tweak the motor or trans on the chassis -- like maybe running over a boulder.