Example #2 of finding myself in a spot where I don't want to make a huge mistake on the river (either by folding the best hand or by putting all my chips in with second best hand) vs losing value by not betting/raising.

Preflop (10 players): Hero is CO with K Q
EP limps, MP limps, Hero raises to $14, EP calls, MP folds

EP is a middle aged moran who's wearing a hunting hat and a hunting mustache and sporting hunting tattoos. He's a good'ol boy. He's run his stack up to $400+ and has my $350 covered. He's been donking flops after preflop raises quite a lot; he's been caught three barrelling in near impossibly bad situations with bottom pair / air multiple times. He will fold when he knows he's beat though. He will eventually lose all his money, it's just a matter of time. He sees me as tight, non-bluffy and perhaps weak/foldy.

Flop (2 players, ~$30): 9 8 5
EP donks $15, Hero calls

With K high against this donker, I could still have the best hand. Two overs, two backdoors, I'm seeing the turn? Any point in raising?

Turn (2 players, ~$60): 4
EP bets $20, Hero calls

Two overs and the second nut flush getting 4:1, so I'm not folding. Still no point in raising?

River (2 players, $100): 2
EP bets $30, Hero...

I've got the 2nd nut flush. While EP is a bluffy moran, he knows just like everyone else there are 4 spades on board plus he knows how to fold when he's beat, especially against me (seen as non-bluffy). Do I have to raise to get value from Q/J flushes? But what if moran thinks Q/J flush might be good and pushes all-in? Is getting the extra value from the one or two hands that *might* pay me off worth getting into a tough spot?

GhavingadifficulttimeontheriverG

I'd raise here. From his description, I think his calling range is a lot wider than just the Q or J. In the long run, not betting or raising with the second nuts will cost you more money in value than you'll lose the few times you run into the nuts.

if you can raise/fold reliably, do that. if you think he's a moron overvaluing Q high flush, minraise and call a reasonable 3bet. otherwise, just call.