How's my line - did I miss a bet here?

[antifish225]

20-40 live, down to 6 handed, UTG is somewhat loose/very aggressive and quite tricky, UTG+1 is similar although his post flop play is very good - both players have correctly increased their aggression now that we are down to 6 handed (playing maybe 30 minutes with 6) - my table image is very tight (tighter than normal as I have seen NO cards for 2.5 hours).....

UTG Raises, UTG +1 reraises, fold, Hero on button with 99 caps the betting, both blinds fold, original raisers call.

Flop 6,8,5 rainbow
check, check, I bet UTG calls, UTG+1 folds

Turn 10 completing the rainbow

UTG checks, I check behind (thinking I should have bet out here, however I am having a hard time putting UTG on a hand, did not want to bet and b cr'd as I still had outs with a 7 for the str8 - also potentially inducing a river bluff)

River - 3

UTG bets, I call (should I have raised this?, thinking maybe)

MHIG - UTG shows 77

How badly did I play this?, should I have bet the turn?, should I have raised the river?

All thoughts are appreciated....