I think this is fine. It's one of the worse flops you can get so I'd prefer to keep the pot smaller. Even though betting for protection is important, so many of your opponents draws will have such high equity on this board that you'll get checkraised tons which is the opposite of what you want. That plus the fact he'll have all sets and you likely don't.

Turn and river are good. With some weaker hands you can bluff the river but I think AA has enough showdown value that the check is good.

Obviously a nasty board!

Vs unknowns I'm taking this same line as you will get raised a ton. If I have enough stats on villain to see that he's passive and never makes post flop raises then I would lead towards betting flop and turn for value.