Joaquin first off you should not have a 1/4 degree of positive incidence it should be 0 degrees .You need to put your incidence meter on the inboard side of each wing and the run the meter out to the wing tip it should read the same all the way out if you have a twisted wing it would cause the wing to drop as you described. The Cg you stated is fine and you can move it back a little further if you like but do it in small amounts.I hope this helps you.