If your preflop raises are getting a lot of callers, then I agree. If you are often winning the blinds and a couple of limps with a preflop pot raise, you give up a bunch of equity. The fact that you have AA2 makes it less likely someone else has something that can stand a raise preflop.

I'm not going to get busted thinking my AA overpair is good.

Comparing AA2x in Omaha to AA in Holdem indicates a serious misunderstanding of odds and betability. With AA preflop in holdem, you are always at least an 80/20 favorite. You can't hope for much better than that, you want to get as much money in as possible -- edges after the flop in Holdem are typically rather small. That is not the case for PLO8; before the flop, AA2 is probably a 60/40 favorite or so over most hands that call a raise. The big edges come after the flop.

Raising or limp-reraising with an AA hand with 100x BB stacks is not a horrible way to go. Against good competition, though, I think there are better ways to play it.