Glad you are getting somewhere.

If you are uncomfortable or the model is incapable if inverted flight another good test for cg is a 45 degree down line. Trim for upright level flight at half to three quarter power. Push over into 45 degree down and release. If the model continues down or steepens move balance forward. If the model pitches up slowly cg is about right, if it pitches up rapidly you could go back a bit.

As I and others say, once your cg is where you want it adjust throw and expo to give you the feel you want.

Dihedral wont affect pitch stability.

Dave H