1500 rpm idle is a bit slow (1700 is normal) Try increasing idle speed a smidge to see if you have a resonance that goes away at a higher idle speed. On the center stand It's OK for the rear wheel to turn a bit at idle, as long as the bike doesn't want to move when you are on it and stopped at a light. You should be able to sit on it and not feel it trying to move when stopped, ie, not need the brake to keep it stopped.