For what it's worth, I think you are on the right track. Add a tiny bit of weight (use tape initially) to the right wing tip to balance the plane in the roll axis, make sure the plane is slightly nose heavy to start with. Note, you can't use your fingers to check the CG with these tiny airplanes, that's just not accurate enough. The 2mm deflection over a 10mm length wing warp could be a factor, can you steam it out or heat up the covering and twist the wing slightly until it cools down? If the incidence angles and the control throws are correct, you have done your homework! Of course you need to fly these micro planes in very still air, even a light breeze will be a real challenge. Good luck!