I built mine in line rich and have had no probs with the tamiya spurs and pinions?? I know a few who have had spur problems and running the ae ones cured the noise issue
As for the belt rubbing on the rear of the slipper plate, i have this and there has been no probs at all, AWESOME CAR!!!!!
keep us informed, have you changed the std silver ball studs too? (bit soft)