bottom two, scary turn card

Stars Cheapie

Villian isnt crazy, but he plays too many hands.

I have a solid image. I called to the river with the idiot end of a straight early, and played solid hands from there. I've shown down QQ, AK, AK, a couple other solid hands. Taken down a few pots with cont bets and the like.

PokerStars No-Limit Hold'em Tourney, Big Blind is t100 (9 handed) FTR converter on zerodivide.cx

CO (t2135)
Button (t3235)
SB (t5855)
Hero (t7430)
UTG (t9275)
UTG+1 (t3391)
MP1 (t335)
MP2 (t8295)
MP3 (t3235)

Preflop: Hero is BB with J[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/club.gif[/img].
<font color="#666666">5 folds</font>, CO calls t100, <font color="#666666">1 fold</font>, SB completes, Hero checks.

Flop: (t300) Q[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets t150</font>, CO calls t150, SB folds.

Turn: (t600) T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t400</font>

This seems to standard, but while I was playing it, I felt like I was butchering it. 1/2 pot to charge the flush draw just felt wrong. I have a vulnerable bottom two that's drawing to 4 outs vs a lot of hands here. Is this bet correct?

Turn comes, and its one of the cards I really didnt want to see. If I check here, any half decent opponent bets, so I've gotta bet unless I plan to shut down, no?

So, start those engines and douse me. If villain calls my bet, he has like ~1400 behind. Plan? What would you have done differently?