At my level players limping PF but willing to call PF raises is common. No reason to think he has PP.

It is true that a ring player wants to see bets on all streets. But in my case I won't overbet the pot. If I were to do that I would usualy get folds all around. If the pot is $.40, Ill bet $.30 and lead out with $.50 on the turn unless I am getting reraised in which case I'll push harder. That certainly isn't over playing it. So I would say it is equaly hard to detect a set in the ring.