wing incidence
I think this is quite possible. I had forgotten that after I covered the plane and mounted the wing to it I found a gap (a hair less than a 1/4 of an inch) between the leading edge and the fuselage. At the time I thought maybe this was to add the weather striping cushion material that I used to see on planes. But now I wonder if he drilled the holes for the two wing dowels too low on the fuselage (or glued the piece in too low). This would give it less angle of attack and I am guessing would cause the excessive elevator trim. I suppose I could quickly fabricate a shim and put it between the trailing edge and the fuselage and see if thing work better. That sounds like a better idea than trying to change the CG (which in my experience can make for a short plane life).
The Great Planes Cherokee 40 kit was discontinued as far as I know. I think its a lot better looking than the Hanger 9 Cherokee ARF. If I get a chance I'll try to post a pic. I do think that the Hanger 9 version is still a good looking plane (especially since its under $140) though and probably would have purchased it instead of buiding a kit if this one wasn't already built.