top two with KQ 5/10, check out my line and tell me what's up

[4betaboutit]

I get dealt KQ spades on the button at a full-ring table at Bodog. No reads except for the fact that everyone at Bodog plays loose and that most are bad. I raise to $40 after 3 limpers- SB calls, BB folds, all 3 limpers call. Flop comes Kh-6c-4c. I bet $90 into $210 pot. It gets folded around to the cut-off, who calls. There were a few reasons why I decided to underbet the pot.
1. I don't want to build a huge pot.
2. I could already be behind to a set or 2-pair. (People routinely limp with K7s-K3s in these games.)
3. By betting light on the flop, king worse kicker will be more apt to call you down on later streets. Also you get underpairs to call.

Turn comes a Q of hearts, giving me top two. CO checks, I bet $250 into a $390 pot. CO calls.

River comes a 7 of hearts(Kh-6c-4c-Qh-7h). CO checks, I bet $300, or about a third of the pot. CO check-raises me all-in for $300 more. I call.

Whaddya think? Let me know if you disagee with either the way I played the hand, or my logic behind it. Thanks.

Seahawks 24 Steelers 20 btw