I say limp. Since you know 3 players will probably call your raise it doesn't pay to raise KQ. With that many callers you don't want to be the aggressor in early position with a hand like KQ. Raising hands like AQ, AK, and KQ, becomes +Ev in late position when you can isolate 1 or two opponents. It's profitable because you get to see how the other players respond and because if you don't connect and they don't raise you can follow your pre-flop aggression with a bet and steal the pot.