I had no engine angle issues just CG issues, and once corrected a thing of beauty. If you do shim the engine you're adding more weight to the nose adjust accordingly. Then finally are you using the wire landing gear that came with the model? It is the worst thing about the model. On take off if one wheel catches a rut it pull that wheel out of alignment (toe out) then the model takes an erratic path that can make for some scary takeoffs an embarrassing . I had to change to something stronger, but also something light. More food for thought.

Steve