i would call river shove, you do not block FD and you only loose against 7Qh or 75 and sets. you can beat all FD and straight draws and even overplayed A10 of.

I would fold! Simply because you are playing 5nl! As Kuca says it is a pretty easy call at 25nl or higher but at 5nl people almost never barrel off on their missed flush draws (as they should)!

I'd fold turn v a reg but call it off v a splashy casual. Bluff catching v those guys is good fun.

You should bet bigger on flop. This is not the right flop texture to let them cheaply see turn. So many cards will hurt your hand.
And it's a fold on turn as played, unless you have reads or he is aggro. NL5 standart regs will shove you 2pairs+ in these spots.

he was bluffing with KJhh, I called

Without any information about the villain, this is just a guessing game. You pretty much have to play this against the image of the average player at your stakes and this is why I'd probably get away from this hand somewhere around the turn, though I'd most likely call this down at higher stakes. I'm glad it worked out that time, and if you had some info on your opponent suggesting that he might be overaggressive than good on you for using that. That being said, your average NL5 guy, should be too passive to pull a play like that off.