1. Again 3 callers. Raise more. You need 1-2. If you get the same pot with less people in it, the only thing that changes if you throw more, is that you got a higher chance to win. Simple statistics

2. Doesn't look like he hit the straight, he woulda raised more if he was a Lagg. So either he got one pair (like A7, K8), or more likely he is chasing an 8-out straight with like A9, K9 in his hands. This means your reraise was insufficient.

He only has to pay $2.5 into a $14.25 pot. That's 17.5%. So he gets good odds to chase his straight here.

3. At the turn, an overcard shows up. This is dangerous, and exactly the reason why you need to force bad odds upon him for seeing the turn at your flop reraise. It is not too unlikely he has the K here. You bet around 1/3 of the pot. Seriously, what is that? If he's still on his straight draw with A5 or A9, you're not discouraging him. If he has a crappy hand that he can doubt (which you have beat) like K2, you're not throwing enough to weed him out either.

4. River. Another overcard. He probably has you beat by now. I put him on A9/A8/A7/A5/K9/K8/K7/K5. Or maybe even AQ/KQ (but I don't think so, he woulda bet the river with those). He was probably planning a check/raise if he had a good hand, or he simply wanted a showdown with a not-so-great hand, which most likely has you beat.