Will setting Fahcore_11.exe*32 to HIGH/REALTIME increase PPD?

Technically no it does not increase your PPD. If you are on your machine while it is running and you set clients to high or real time priority it could cause lagging in certain applications. On the good side it will prevent other programs from stealing resources. If you do have things stealing resources that the folding client needs it could increase PPD by a smidgen.