Party Poker No-Limit Hold'em, $0.04 BB (6 handed) - Party-Poker Converter Tool from http://www.flopturnriver.com

CO ($10.01)
Hero (Button) ($4.79)
SB ($4)
BB ($4.55)
UTG ($4.32)
MP ($5.55)

Preflop: Hero is Button with J, K
1 fold, MP bets $0.16, CO calls $0.16, Hero calls $0.16, 2 folds

Flop: ($0.54) 7, 2, 6 (3 players)
MP checks, CO checks, Hero bets $0.26, MP calls $0.26, 1 fold

Turn: ($1.06) 4 (2 players)
MP checks, Hero bets $0.75, MP calls $0.75

River: ($2.56) 8 (2 players)
MP bets $2.12, Hero ???

MP is 15/9 (56 hands)
CO is 57/19 (88 hands)

My questions...

1) Was my flat call pre-flop here good? I thought about a 3-bet to try and isolate the CO but the open from MP had be thinking a slightly more cautious play was in order.. is my thinking good here?

2) I bet the flop and turn mostly because I expected CO to call light. When MP called the turn bet I wasn't sure what to make of it, but thought more than likely he has an overpaid, or made a set. A straight draw that made on the river was also possible. My thinking was that MP probably didn't think I had flush cards being that I led out at the flop. Did I make mistakes here too?

3) Is anybody folding at the river?