1. Fold pre-flop. Hand could be playable in late position, but definitely not under the gun.
2. Fold pre-flop. When you decided to play the hand, I personally would have fired again on the turn instead of checking behind if you have a good read on the guy that he is not a check-raiser. IMHO his call either said, "I am on a draw," "I have an ace with a crappy kicker," or "I am a slow-playing a monster." I think the chance of "C" was low, and you could have found out real quick by firing out a bigger turn bet. Basically you gave up the hand after the flop, unless a club came. I dunno, you have position...use it! But ideally, don't put yourself in that situation....fold preflop!
3. Fold-preflop, although I personally have an affection for the suited gappers. However, you usually need a few people in the pot to make them profitable. I notice you have a nasty habit of limping in pre-flop. It's tough, but usually when you are the first in the pot, put in a raise. Especially when you are in early position, you are not going to have an advantage during the rest of the hand. Give yourself at least the advantage of being able to fire out a continuation bet by raising pre-flop.
4. Okay, though you might want to fire out a smallish bet on the flop. Based on the previous hands, these people will call a flop bet with any old crap, so why not get a little more money in there?
5. I would bet a little more on the flop. Baby flushes are vulnerable, you probably don't want him seeing another card. If he had the Ace high flush draw, he was probably coming anyway, but don't make it so cheap for him to do so.
6. Definitely raise more pre-flop. With a vulnerable pocket pair, you want the flop action to be heads-up....Given the way you did play it, when the King comes on the flop, I think you made the right move by check folding.