just calling w/ the nuts in a multi-way pot

[nut case ace]

6/12 at Hollywood Park.

Pretty good game. plenty of weak loose-passives, etc. There is a whole lot of limping going on in this game and a whole lot of chasing.

PREFLOP: Hero has Ad3d on Button.

4 limpers to me, I limp, SB completes, BB raises, everyone calls.

FLOP: Ah-Jd-6d

Great flop. 5 checks, CO bets, I call, 3 calls.

Turn: Ah-Jd-6d-8d

nutty. 3 checks, CO bets, I call, SB calls.

River: Ah-Jd-6d-8d-2c

Checks to me, I bet.

So obviously my questions are about the flop and the turn. On the flop should i be more concerned about getting keeping the field large so that when i hit i win big or should i be limiting the field so that I can maybe win w/ my top pair when i dont hit? Similarly, on the turn should i just start pumping it and hope some of the EPs have enough to call my raise? Also, in a game this soft the preflop limp is correct, right?