Here are my observations - First, are you referencing wing incidence to the engine thrust line? Is the thrust line referenced to the 0/0 center of the fuselage? Wing incidence will raise or lower the stab flying position. For a given airspeed the wing angle of attack will be the same - change the incidence and the wing will seek the same angle of attack again for that airspeed. The difference is the stab will be higher or lower (as seen in the air) than before. You will then adjust the stabs to seek a 0/0 with new the elevator position. You can then change the engine thrust a bit to get the plane to fly like you want it. The perception of level flight, upright and inverted, can be changed by wing incidence. If you mix in CG changes, the general theory holds, but less wing incidence may be required to make the plane fly level.

sc