If you shim the wing, remember that on a flying boat the wing saddle is where the water gets in. Silicone sealer and saran wrap to restore the seal.

Upthrust is good. Last flying boat I had wound up with about 3 degrees up, and 3 right. That's part of the reason for a t-tail: gets the tailfeaters into the prop blast so that the decalage od the motor mount has an immediate effect on the control surfaces.