Great work! I`m amazed by physics. All the tricks i know work good and the rest seem to work well. About mouse and keyboard i would suggest a static aproach like in Condor Competition Simulator - it`s intuitive and very responsiwe. No need to constantly drag mouse or repress keys to maintain steady circle. I suggest mouse up > speed, left/right > direction, down > brakes - this would fit all controlls needed in a single hand.