Yep, I'll agree with BillS on this one. 12 clicks up trim and only 1/2 degree off at the most indicates also to me that you are more nose heavy than you think. Down thrust could also be an issue.

I would now suggest the CG be rechecked and that you are checking it with the tank empty and with the plane inverted. Try to get the CG as close as possible in the middle of the recommended range.

If the amount of trim is still to much then start flying using a good trim chart. It takes allot of time and fuel to work with a trim chart but by the time you are done you will have a great flying plane. It helps to have to people while trimming. One flying and the other taking notes.

Also, are the ailerons set correctly?