Hi CORO, Are all the flying surfaces good and stiff? If you have loose, buckling surfaces it's going to be a handfull and get worse with speed. Most planes are in their comfort zone if the CG is 25% back [of the wings chord[including ailerons]] from the leading edge. I know you said that you thought it was nose heavy, do the math and place marks were the CG should be, then compare. Almost anything can be trimmed to behave halfway decent if the controls are tight, the surfaces are stiff, and the CG is in the ballpark. The incidences are easy enough to check with a ruler working off of a nice flat work table. The engine thrust can be checked by positioning the prop vertical,[the fuselage and wing should already be level] then grab a triangle, or square and back away from the plane some. Looking at the square and the prop in the background, you should be able to eyeball it. Absolute perfection isn't necessary, but if you have stuff a little out of whack everywhere, then all this will stack up against you.