RE: Thrust ???
After checking the setup on my buddies airplane, I noticed that he had to trim in considerable up elevator to fly straight-and-level at cruise speed... When inverted, it dives for to the ground... He has CG set at roughly 2" behind recommended, but it still acts nose heavy... Strange... Could be an incidence issue, but I will advise him to try the techniques you guys have outlined to isolate the problem...