How would you play this?

[mongidig]

live 20-40 9 handed. I have a tight image. I have only raised a couple times and have shown down KK and AK. I am card dead so I haven't been in many hands.

UTG limps(She is decent but too loose preflop. She will play any broadway, pairs and many suited connectors from this position. She turns into a calling station post flop and will check call all the way with as little as bottom pair although usually has better than this including top pair. When she bets she has a strong hand.) MP raises(He is tight and passive, will have AQ,AK, or big pocket pair here. He is very straightforward post flop and easy to read. He never bets his overcards if he missed but will check call all the way with them.) It is folded to me on the button and I call with 99. The blinds both call(They are both a little too loose preflop but decent postflop.) UTG calls.

The flop: 8cTd4h

Checked to me and I bet, blinds fold, UTG calls, MP calls.

The turn: 8cTd4h3s

I bet, UTG calls, MP calls.

The river: 8cTd4h3s3c

We all check.

My first question would be preflop. Should I have three bet or folded? I thought about three betting and figured there was a decent chance to get the blinds out since they respected my raises but figured UTG would call for sure. I also figured there was about a 50% chance or better that MP held a big pocket pair. I figured by calling I would have a decent chance of getting 5 way action and could reavaluate the situation post flop.

My second question is should I have bet the river?