another full house tale

I limped with KJo in late position.
The big blind raised, and four of us saw the flop.
KKT, with 2 diamonds.
The big blind bet and it was folded to me.
The player in the big blind is a fish; I've played with him a lot. His pre-flop raises -- even from the blind -- are highly suspect. So I didn't put him on much of a hand. I smooth-called, planning to raise the turn.
The turn was Ace of diamonds, putting three diamonds on the board. He checked, I bet, he called.
River was Jack of diamonds, putting four parts to a straight flush on board.
He bet.
I made my full house, but with such a scary board (Queen of diamonds makes a straight flush), didn't feel like I could raise (if he had checked, I would have been likely to check it back). But, knowing the opponent, there was no way I could lay down a full house.
I called, he showed KQo - he flopped trips, and made the straight on the river.
I got lucky to win the hand.

Here's what I don't like about how he played the hand:
1) raising KQo from the big blind with 3 limpers is a bad play.
2) checking the turn is a bad play, unless you are sure your 1 opponent will bet and you plan to check-raise
3) smooth calling the turn is a bad play. If you believe you have the best hand, you have to raise; if you're beat, you have to fold.
4) betting the river with four parts to a straight flush on board -- holding a straight -- is dumb; the only hands that can call you either tie or beat you. A better play would be to check. A straight may be strong enough as a 'bluff catcher' on this board, though, with four diamonds on the board, it's too easy to lose to a flush. And, the highly coordinated nature of the board makes it likely that a full house is out there. Or even a straight flush.