RE: OS 52 FS RPM
We can't tell you the RPM level your three-bladed prop will turn. What we can say is that you should target a full-throttle RPM in the high-9,000's or low 10,000's when the engine is leaned to just rich of peak RPM. That tells you the propeller is suitable for the engine's ability to turn it. If it flies the airplane the way you want, then it's the correct propeller to use.
In all cases, regardless of the type of propeller, you should target an RPM range, then select a propeller that will allow the engine to run there, and finally see how that combination will fly the model.