Wow! This thread got complicated in a hurry. We habdy a guy diagnosing thrust line issues even though no thrust line test has been done, and another who wants to redesign the wing mount to keep from having to adjust the elevator trim. Both might make sense in other scenarios, but are not called for here.

The truth is that the way the elevator needs to be trimmed on a maiden has very little to do with whether the plane is set up right. CG is 100% about pitch stability. If the plane glides smoothly and drops its nose gently on a landing approach but you still have enough elevator to flare then you aren't too nose heavy. I start at 25% and move it back until I get that kind of response. On a trainer, that's usually around 26-27% MAC. You check for a thrust issue by letting off the throttle and watch the nose. But your climbing issue was nothing more than the elevator trim being a bit off from where it needed to be for that plane.