KQs in BB unopened pot

[Gurravasa]

UTG=49/13/0,6 45 hands
MP=44/22/0,9 108 hands
SB=31/25/2,6 1200 hands, overaggro postflop with 45% W$ASD and 32% WTSD! My feeling is that he just always choose the wrong spots to get aggressive.

Full Tilt 2/4 Hold'em (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Preflop: Gurravasa is BB with Q[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG calls, MP calls, <font color="#666666">2 folds</font>, SB completes, Gurravasa checks.

Flop: (4 SB) Q[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets</font>, Gurravasa

Is this a always a raise pf? Don't really know how I reasoned when I just checked and I can't get the arguments straight in my head right now either. We sure have equity to raise but we are OOP. Raising should give us foldequity but since it's 4-handed we can't expect to pick this up on the flop UI. Also is there any extra value to gain postflop with a hand that plays well postflop in multiwaypots if you don't show agression pf? I just feel I should raise but I want to check up the reasoning about why...

Finally what line do you choose for the rest of the hand as played?