Set of 7's on a scary board

[restless]

Reads:
SB & BB - mostly weak tight
UTG - Tight & solid
MP - LAG on the rebound :-) Has played very LAGgy earlier, slowed down somewhat now, but still pretty aggressive & bluffy. Especially against me, we have some history at the table.

Texas Holdem $0.5/$1.0 6-max

Hero is dealt 7/images/graemlins/spade.gif 7/images/graemlins/diamond.gif in CO
UTG calls. MP calls. Hero calls. Button folds. SB completes. BB checks.

Flop (5 SB) 7/images/graemlins/club.gif 9/images/graemlins/diamond.gif 6/images/graemlins/club.gif (5 players)
SB bets. BB calls. UTG calls. MP calls. Hero raises. SB calls. BB calls. UTG calls. MP calls.

Turn (7.5 BB) 4/images/graemlins/club.gif (5 players)
SB checks. BB checks. UTG checks. MP checks. Hero bets. SB calls. BB calls. UTG folds. MP raises. Hero 3-bets. SB folds. BB folds. MP calls.

River (15.5 BB) 8/images/graemlins/diamond.gif (2 players)
MP bets. Hero calls.

Questions:
Preflop: Is this a raise?

Flop: Should I just call the flop bet & raise a blank turn instead? I mainly raised for value, but maybe I ruined my chances to clean up on the turn. I don't think that MP would have folded anything though based on our many raising wars lately...

Turn: I tried to isolate MP cause I knew he may be betting a worse hand here. I also had outs to the boat ofcourse

River: Called & expected to see a straight or a flush. Anyone raise here?

[bds]

Preflop, I raise this everytime. I also raise on the flop. I bet the turn, call a raise and call river bet, expecting to be beat often but also winning enough to make it a profitable way to play the hand.