New,
Cooling holes in the fuse are good! try to have 2-3 time the area of the intake holes for the hot air to exit
380 sized motors are also called speed 400, the difference usually being the 380 has had the back removed, and a metal back w/bearings put in it's place. Graupner is a good inexpensive one, available for 9.99 here at the LHS, and if you check Model Airplane news or one of the magazines, you'll find all kinds of places to order them. Let me know if you find what you need.

All I can offer about the prop "windmilling, is make sure your trim on the throttle is all the way down.

Jetts