a common situation - OOP, middle pocket pair

[highland]

So, I just played a hand and I realize this is an exceptionally common situation. I usually take this line, but I think my river play (at least) is a leak.

50/100 online:
MP1 limps, I raise with 99, MP3 reraises, folded to MP1 who calls 2, Hero calls.

3 to the flop for 10.5 SBs
[ 7c 7h 5c ]

MP1 checks, Hero bets, MP3 raises, MP1 folds, Hero calls

Turn 7.25 BBs (2 players)
[ 7c 7h 5c ] [ Qd ]
Hero checks, MP3 bets, Hero calls

River (2 players, 9.25 BBs)
[ 7c 7h 5c ] [ Qd ] [ 2d ]
Hero checks intending to call a bet

In this case, I have almost no stats on my opponents (a slight indication that they are weakish). My 25 hands on MP3 are 20/10, some 7handed, i think.

On the flop, there's a medium sized pot, and I'm hoping that MP3 will raise my bet forcing MP1 to fold what are quite often 2 overcards to my 9s.

On the turn I think I'm probably ahead, but I'm not sure I like betting out or c/r'ing. If my c/r is 3-bet, can I fold when MP3 could hold AcXc?

I think my river play is poor. I would rather have bet out and folded to a raise here. Almost all players will check behind their ace-high hands, and AK will often call a bet. I doubt I'm bluff-raised here very often. Suggestions on a good standard line for this hand, and alterations based on MP3s inclinations?

cheers,
highland