vs someone who limped in, you can assume he is a recreational player and just go for 3 streets of value on a lot of runouts. As played, you should also look to increase your sizing to get value from his worse hands on the turn. Think you can go quite a bit bigger on the river as he's never folding a flush and probably not folding a king

I'd go all in on the river. Villain is pretty much repping a king or a flush and I doubt that recreational player folds those hands to any size. So I feel like your sizing is a pretty big mistake because we could get a lot more value by shoving.

I even thought to shove, but it'll probably make not nut flushes fold.

I'd bet a lot of money againts this statement, I really doubt that an average NL5 fish folds flushes to a shove. Or even a Kx. I think you're projecting your own game to your opponent, which is a big mistake againts a player who probably plays very different to you and could potentially just be like "eh, 5 bucks, who cares".

I pretty much agree with both posters above...In general, I don't think you should be too worried about this player folding flushes. That said, I probably wouldn't raise quite all-in here...perhaps 5x his bet to something around 2.50?

But as also stated, this decision could be made a little easier if you bet the flop and/or bet bigger on the turn. I think turn you can go closer to 2/3 to full pot...Many players will still call with all of their pairs and all of their flush draws here, especially after you checked back that flop and the top card pairs.

I'm also quite curious about the preflop iso here. I iso a ton myself in weak games, but I am often unsure of just how wide to go. Presumably this player is weak (even more reason to consider betting flop), but I am not sure what I would/should do with KTo here on the button. I am curious what others think: How wide do you raise button here? What hands do you just limp?