NL200.. When to lay down AA post-flop?

[pamponet]

I moved to NL200 and one of my biggest problem is to figure out when it is time to let go AA or KK. At NL100, I could push AA pretty hard on the flop and get called by weak or drawing hands and this play was profitable (off course I ran into a set every once in a while). However, at NL200, I just don't get called as much with weak hands so I have to worry a bit more when my pot-size bet gets called.

So I'd like to know at what point do you realize that you're beat and it's best to laydown your big pocket pair.

Here's a fictive hand:

You're playing at a full NL200 table that you joined a few hands ago, so no reads.

You're in EP and get dealt AsAc. You raise to 8$. Everyone folds except the button and the small blind.

Pot is 26$

Flop: Jh 9h 2c

SB checks.
You bet 25$.
Button calls. SB folds.

Turn: 4s (Pot is 76$)

What is your move here? I hate to just check here because it shows weakness and he might throw a big bet. But since he called a pot-size bet, I have to worry about a set and I don't want to lose too much money. The flush draw is possible but he would have called with bad odds.

Scenario 1)

You check. He bets 50$. What's your move?

Scenario 2)

You bet 50$. He calls. River is a rag. What's your move on the river?

Scenario 3)

You bet 50$. He raises to 100$. I guess you fold here putting him on JJ or 99?

Scenario 4)

Let's suppose that instead of calling on the flop, the button min-raised you to 50$. Can you fold here? 25$ for a pot of 101$.. 4:1. If you call, what is your move on the river?

1) push
2)check/fold? perhaps call
3)fold the min raise is bad 4 u
4)again min raise bad for u fold if not fold push