4bb+1bb per limper is what I use PF like slevin said. You definitely don't want everyone to fold PF (you have the nuts as of then, so you want to get as much money in as possible) but you don't want 5 people seeing the flop either.

I wouldn't c/f here ever I don't think just for the simple fact that neither opponent showed any more aggression on the flop (unless obviously they are slowplaying which is a possibility, but meh shit happens, get over it)

With the size of the pot and your stack sizes a ship is probably a good idea. I'd just stick it in and make moniez.