WROB : Try keeping a little more RPM on on your landings. Also set the CG at 85 mm and it should work fine.
They do have a tendency to bounce a bit if you are to slow. I've owned a few of them and I really enjoyed them.

I never had a vibration problem either, but I never had a 4cyl on mine either, sounds like you may have a problem maybe with the prop or the way you mounted the engine.

As far as indexing the wing, if it's set in right and tightened tight, you won't have a problem. ENJOY !!! RED