Given the player I think it's fine. He was obviously a big goon and so after he bets twice you can put him on a large range (rather than, say, top set). I might bet even less on the river but he seems to suck enough to make it profitable!

Usually I'd lead this flop - the reason being you hold the K of the flush suit, so your big "payoff card" is in someone else's hand. The priority for me therefore becomes making any set or two pair pay. With the A and the K it's less likely to be bet by somebody and if someone does bet, they're less likely to pay you off on later streets so, again, I'm keen to ensure the bet is large enough to discourage at least 2 pairs (and hopefully also sets) from getting involved.

I'm quite surprised playing at Stars as I believe you do that you'd run into such an awful player, last few times I've sat in a 200 game there they've been pretty solid. Maybe I should keep an eye on it more often.