RE: 50CC Extra 300 snap
David, 2 degrees difference is pretty large. I don't think that it's a cause of your snaps but it will create issues. Not knowing if it is positive or negitive I really can't say what the ill effects are going to be. On my aerobatic models I set the stabs and engine to zero and the wing at +.5. Reason for this is that the wing needs positive incidence to support the weight of the airplane. You can set everything to zero but then you would need to fly the whole airplane at a positive angle. IMO this makes it harder to get knife edge and verticals on the money. You may want to correct that 2 degrees before anything else. I do however feel that the snap issue is just over application of elevator. Your wing incidence could be masking a nose heavy condition as well.