Preflop
I would always defend 76s to a normal open up to say 3BB. But when you are facing a 5BB open, you are not getting a good price, and you are going to be out of position postflop against probably two opponents. I know, low stakes live players regularly call in spots like this. But barring live dynamics, where you might need to "give action to get action", there is no way, this call is ever going to make you money.
Flop
Checking to the preflop raiser is obviously standard, and the plan would then be to go for a check-raise, since you flopped the nuts. But I actually dont mind leading on this board. Its a low and very coordinated board, which favour your range, and I dont think, it will always be C-bet. I would not use the thought process, that leading looks bluffy, but I do think, you can get action from at least some
hands, that might otherwise just have checked back. Like his AK/AQ, that sort of stuff. And if he has an overpair or a set, he is probably going to raise you, which is of course fantastic.
Turn
I am not to worried about the board pairing, because I think, most people would have raised the flop with two pair or a set. So I think, you almost always still have the best hand, and I would bet it for value. Leading the flop and then checking the turn to induce is overthinking the situation in my opinion. If he has an overpair, he might actually get scared of the paired board and check back, and if you thought, he was very bluffy, why did you not check to him on the flop?
River
As played I would clearly bet again for value, but I am not really on board with your thought process, that full pot "looks bluffy". In my experience recreational players love to bet full pot, when they are strong, so if anything I probably overfold slightly to that sizing. I feel, you are either overthinking the hand or trying to make up for lost value on the turn and looking for a reason to justify your turn check.
Anyways when he raise and put you all in, I think, its a relatively easy fold. I am still not to worried about boats, because I think, sets and two pair raise the flop, so the most likely boat is a cautiously played QQ. But I think, he can have all 16 combos of JT, and I dont think, trips check back the turn on such a wet board. So you only beat a
bluff, and a line like this in the micros is almost never a bluff. You are also not getting a good price getting only around 2:1.
Results
So you did in fact run into a slowplayed set, and this is definitely something, you will see in the low end of the micros. People playing very passively with big hands on the early streets, and then all hell breaks loose on the river. And this is why, we can just fold to that river raise and not worry about getting bluffed. The funny thing about this hand is, you were both trying to slowplay, and realistically all the chips should have gone in on the turn if not on the flop. In which case you would also have gotten stacked. But because the action was delayed, and JT came in, you actually had a chance to get away, and not taking that chance is a fairly costly mistake.