TLH101:

As luck would have it, for the most balanced aerobatic performance everything should be at zero. Including the engine thrust line and the dihedral.

The wing you're using already has dihedral, so, keeping it simple, don't change it. And with a "Stick" fuselage design the engine thrust line is going to be below the wing centerline.

While some down thrust will allow you to avoid trimming the elevator for power changes, when you go inverted all those trims, and the down thrust, will be working against you.

For the best upright/inverted balance, the wing and stab are at zero incidence, directly in line one with the other, and the engine thrust line is also on the same center.

This last cannot be accomplished with the "Standard" stick fuselage, and having the prop centerline below the wing/stab centerline a very slight amount of downthrust can help. Amount to be determined by experiment, but if you start with one degree you'll probably be so close you wont change it later. two degrees? Maybe.

Bill.

PS: If you want to use some out thrust, that's OK. Twinman swears by out thrust, I don't use it. wr.