Preflop:
- UTG min. raise, three cold calls plus the blinds; tells me it is doubtful anyone but UTG has a big pair as they would not want to play multi-way and would likely reraise.
- Everyone is likely to be on big card draws or middle pairs
- Total pot 1000

Flop:
- you bet 700 and get called by BB only.
- The flop missed UTG and two cold callers so they fold. Tells me spades are live but straight draws are probably unlikely. I’m assuming that UTG and/or the two cold callers folded at least one or two Aces, Queens and Jacks but probably not spades.
- Betting 700 into a 1000 pot, you have to have a decent piece of the pot or a big draw. You wouldn’t mind winning it there, but you maybe wouldn’t mind a caller either. Maybe AsKx, KxQs or AsQs or an outside chance of QsJs. Possible that you have JJ, but you would have probably reraised preflop.
- In my limited experience, a flop cold call like this usually indicates a pretty strong hand. The opponent knows full well that any of the 3 other players could be check-raising, yet he cold calls. Hmmmmm.
- I put the opponent on some kind of Ten that is good enough to play 5-handed with all limpers preflop. Maybe JT with or without a spade, or some other fair to midland Ten.

Turn:
- pot is 2400, opponent bets 1500, offering you about 8:3, just enough to make you make a tough call if still needing a spade.
- Opponent is vulnerable to the flush draw if he indeed does have a Ten.
- You call. I don’t think you make this call with an AK, unless you have the Ace of spades. Further, I don’t think you make this call with a made flush. You would surely reraise because you are vulnerable to the full house draw. To make this call, you need the implied odds from being able to extract a bet on the river if you flush.

River:
- pot is 5400 and opponent checks
- Opponent likely has unimproved set of Tens, but has boated if he possibly played something like T7, but I think that is unlikely
- Whether to bet the turn depends primarily on the likelihood that your opponent would check-raise with a boat against your possible flush, or fold 3-Tens against your flush or AK steal.
- From your edit I suspect that your opponent has a hand, and also was sick of getting beat up on the week before, and will likely call any bet you make or reraise if he has made a boat on the river. Therefore, I bet the flush and check the AK. However, if he has shown a history of being able to check raise the nuts on the river, then I also seriously consider checking the flush too.
- Bottom line is that I’m reading you for AsKx or KxQs and a check, probably the AsKx.

Just my own wrong opinion. I'm probably wrong because I'm still not good at reading hands and tend to get fixed on one or two hands early. Thanks for the opportunity to think about your hand. Even if I’m wrong (likely), it helps me to think about it.