Is a flop bet mandated here?

[bronxbomber]

In retrospect, I wish I had bet the flop (overcards and inside flush draw), but with that many callers preflop, I figured there was a high chance for a check-raise slowplay or turn-card danger from someone. Any thoughts? Is a flop bet mandated?

Ultimate Bet 0.50/1 Hold'em (10 handed) converter

Preflop: Hero is CO with Q[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">2 folds</font>, UTG+2 calls, <font color="#666666">1 fold</font>, MP2 calls, MP3 calls, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, SB calls, UTG+2 calls, MP2 calls, MP3 calls.

Flop: (11 SB) 4[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(6 players)</font>
BB checks, UTG+2 checks, MP2 checks, MP3 checks, Hero checks.

Turn: (5.50 BB) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(6 players)</font>
BB checks, UTG+2 checks, MP2 checks, MP3 checks, <font color="#CC3333">Hero bets</font>, BB folds, UTG+2 folds, MP2 calls, MP3 folds.

River: (7.50 BB) 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
MP2 checks, Hero checks.

Final Pot: 7.50 BB