If would say to absolutely correct your right thrust, IMHO this is one of the most important aspect in order to fly precisely. Regarding CG,I think the inverted flight test is not accurate: you say you have to keep a large amount of down elevator, but here EXPO settings may render the test misleading. If you have a great amount of expo, a great stick travel could lead to a little elevator throw. For CG, I prefer the following well-known test: 45 deg. climb with throttle applied (the amount used to trim for level flight) then do an half roll and let the plane go: it should follow 45 deg climbing line, with tendency to falls down.

Hope this helps! Keep us informed about your results...