[Nick C]

Here's my take on the hand.

Preflop: The raise is fine. KQs is a good multiway hand, even out of position.

Flop: Good bet. I don't have a problem with the 3-bet, either. I'm not crazy about the coordination of the 4 and 5, and I don't know to what extent suits were a factor, but you are likely ahead. It so happens that SB flopped a good draw, but there will be times when none of your three remaining opponents (I think you had three opponents left when the action got back to you) will have such a good draw. Instead, you may be facing a combination of one pair hands hoping for a second pair or trips, gutshots, unpaired ace-rags, pocket pairs chasing a set, and even backdoor flushes. Some of these holdings will have the odds to chase, given the pot size, but there's not much you can do about that. From the sounds of it (in one of your follow-up posts), MP is likely to slow down on the turn, so it doesn't sound like waiting for a "safe" card and betting again in the hopes MP will raise again with an inferior hand will be successful. It's hard to know what's out there, but if you currently have the best hand and there are a full 20 cards (an oversimplified hypothetical estimation) you need to dodge on the turn and river, you'll still end up with the best hand almost a third of the time. Since there's not much you can do to protect your hand, I think going ahead and getting more money in while there's a good chance you have an edge is fine.

Turn: That ace is a bad card for you. If (as you describe) MP will bet if you check to him but will just call (when behind) if you bet, then I don't think you lose anything by checking and calling.

River: I'd hope SB just caught a worse two pair but would be worried about JT and would probably just call.

Anyway, at loose and wild tables you're going to lose to some very weak starting cards from time to time. (I also once lost in a huge pot with KQs to 32o. It was capped with something like eight players in preflop. The person who capped preflop had 32o and ended up chopping with someone else who had 32s. It was expensive for me, since I they both flopped a wheel [and the guy who flopped a set of aces wasn't slowing down either] and I was in all the way to the river with my nut flush draw [and in fact was doing some of the postflop betting myself].) But, if you're playing well, you'll win your share of big pots at such tables and come out ahead in the long run.