i cant answer the 1st or 3rd questions sorry, but for the engine, if ur just bashing or amatuer racing(lenient rules) the os.18cvrx is fantastic. stupid amounts of low end, good mid and a pretty strong upper end. reliable as anything. it can be run a bit rich to help control traction and look after the motor, and still idle for 30+ seconds. starts 1st or 2nd pull every time once primed too. i use a fuel called pro-glow here in australia. 20%nitro and 16oil. mostly synthetic. put nearly 5 litres through the engine so far and still has all its compression.