Thanks for all the great posts and links guys. I figured out the Stuka after ~4 hours worth of tinkering. Turns out that I needed to pull out the top left yellow lever (the name escapes me currently) and keep the engine pressure under 1 bar. RPM was controlled primarily with the prop pitch, keep it around 2200 and be very gentle with the throttle. As far as the strange Bf-110 shuddering, who knows
Thanks again!