First off are you measuring the wing's incidence angle using the straight line that runs directly from the leading edge to the trailing edge?

It may also be that since this model was intended as a fairly neutral handling fast sport model you are intended to fudge in the longitudinal dihedral or decalage with a nudge of up trim.

The downthrust angles seem overly high but it may be due to the engines being located close to the CG where the thrust offset requires more angle to achieve the desired effect. On top of that the thrust lines are so low that this may also produce an upwards pitching couple. Still, 8 degrees does seem like a lot.