Without claying will the ssr2.5 or 3 take off most of the rough surface on a vehicle without causing damage? Also what speed do you find to be most affective for these polishes on your PC?
You WILL remove some clearcoat in the process of using either one of those products. That is not "damage" IMO, but removing too much could be considered damaging.
Use at LEAST speed 5 on the PC for either of those, or any polishes really.