You don't need to clean the primer pockets. Some people still do that, but none of them can give you any other reason other than "I like to."
I like to.
I've been strongly thinking about going progressive myself. (I don't see the point in a turret press, btw - maybe it's a rifle thing. I only load pistol.) But I'm so set in my ways with brass prep, and hand priming, and my powder drop-n-check method, etc. I'm just really hesitant to take that leap.