RE: speed for regular guys
Nick,
If its overheating it is either simply a bit lean or you are getting air bubbles in the fuel (foam in the tank). Make sure the fuel tank is packed well in foam rubber and does not touch anything (or use a bubble-free tank). Toward the end of the tank (with a conventional fuel tank) the engine will start to go lean the moment it gets a few air bubbles from the clunk bouncing around. Its time to throttle back and land at that point.
Richen up a bit. You want to launch 400-600 rpm down from peak rpm - it will unload in the air, and it needs the fuel as the rpm spools up. If you find this is generally not enough, investigate the fuel foam and bubble issue a bit.
We typically do not recommend anything more than 15% nitro for the engines, but you should be ok with the heli fuel (it already has a ton of oil in it).