$11: Top pair on scary board; what's my move?

[Pokey]

I'm in the big blind with A [img]/images/graemlins/spade.gif[/img] 3 [img]/images/graemlins/heart.gif[/img]. Blinds are t15 and t30, seven players remain. Hijack limps, CO limps, button folds, SB completes, I check. Flop comes:

Q [img]/images/graemlins/club.gif[/img] J [img]/images/graemlins/spade.gif[/img] A [img]/images/graemlins/diamond.gif[/img]

Stacks are:
SB: 1,865
Me: 745
Hijack: 920
CO: 690

I've hit top pair with no kicker, but the QJ on board make it less likely my kicker will play. SB checks, I bet t90 into a pot of t120. Hijack folds, CO calls, SB folds. Turn card comes:

Q [img]/images/graemlins/club.gif[/img] J [img]/images/graemlins/spade.gif[/img] A [img]/images/graemlins/diamond.gif[/img] K [img]/images/graemlins/club.gif[/img]

At this point, A = A unless he's got a decent kicker.

I check, CO checks.

River card:

Q [img]/images/graemlins/club.gif[/img] J [img]/images/graemlins/spade.gif[/img] A [img]/images/graemlins/diamond.gif[/img] K [img]/images/graemlins/club.gif[/img] 7 [img]/images/graemlins/spade.gif[/img]

Total blank. A few questions:

1. Flop bet: bad idea or good idea? Was t90 too small, too big, or about right?
2. Turn: check/fold or bet it? If "bet," how much is right?
3. River: check/fold, check/call, or bet it?

The only read I had on CO was that he played a bit loose (VPIP 30%) and passively (AF = 1.00).