villain: seems like a tightish rec player. been playing with him for 3-4 orbits.
asian guy in mid 50's
hero: been picking up some good hands so i have a high 3bet freq. hands havent gone to showdown much and nothing crazy happening. table is pretty nitty.

hand: villian opens 30 hj, co calls. i 3bet to 120 otb with ak with k of clubs. villian calls. co folds.
flop is a510cc. i cbet 160. villian calls.
turn is a offsuit q he checks. i check back thinking i pretty much only beat aj at this point.
rivers comes 7 of clubs. i could bet smallish like 1/3 pot to get crying call from aj or some other ax hands. pretty rare that he shows up with ax since i think hes pretty tight. but its possible. also he could call with maybe qj altho he would fold the flop a lot wit qj and might just muck pre.

or i could check with the intention of folding since flushes are a large part of his range and i dont think he would turn a made hand into a bluff. and i dont think he would have complete air here very often at all and i dont think he would bluff complete air. these types of players just check back missed hands all the time.

last question is. not strictly regarding this hand, but is it good or ok to take a line with maybe slightly lower ev if we know we are never getting bluffed or valuebet in a certain spot. so we are playing perfectly against an opponent

1) Stack Sizes
2) Good luck check/folding on the button
3) A line won't be lower EV if we are playing perfectly against an opponent

Need stack sizes.
But probably B/F turn.
Check back river/fold

bet turn he will have turned equity a lot if he had draw on flop. fold to raise. if ur thinking u can only get value from AJ that's way too nitty and it's a small part of his range since he called 3b OOP. a lot of the suited connectors he calls pre with now have a gutshot, or they had one on flop.

QJs/J9s/JTs/T9s/98s and suited wheel draw all calling turn. ace may call sometimes too as you have draws in your range.

checking back river is a huge mistake, especially if you check turn. You can actually go fairly large on river as our hand is underrepped and no ace is folding. queen might not either.

you can't vbet 3x in hand though but need to get 2 streets for sure.

it's never good to take a lower EV line from a money-making perspective. it's actually deviating from perfect poker. taking lower EV lines to say, reduce variance is fine though.

eff stacks were 1.2k

Is the A on the flop a club?

You need to get the positions / action straight for us to be able to give you an answer.

Hi dgaf, Where's the iceman avatar?

B/c the Turn b/c we have top top

Hi rakes, I'm still going to have to call traveling on your avatar.

WRT the hand, I'd make villain go first on the river.

Interesting hand but need to clear up if you are in position or not. Based on turn action you are but river and flop says the opposite.

If A is A of clubs is also important because it massively changes how many flushes you each have in your ranges

I'll try to address all the options.

If he checked to you on the river then b/f is best as I'm never worried about getting c/r bluffed by this villain. In terms of sizing if villain is ABC I'm going small-medium to get called by weak Ax and smaller pairs. If villain is more thinking i like an overbet. 1.5x pot to make your hand look like a bluff. look like you are trying to rep a flush on a scary river card but you don't have a ton of flushes after turn x/b. He will think you are polarized and your line doesn't make much sense and hero call.

If you are OOP on the river then i like a medium sized bet looking to get called by worse Ax and other stuff.

Nah, that's poor etiquette imo. He went first pre, we went first OTF and he went first OTT so it's clearly our turn, as OP states when he considers block betting vs check / folding from the button.

I mean I get that, taking turns/sharing is the right thing to do obv, but in this case with this specific decision I'd really rather him go first because I'm not in a great place stress wise, so maybe instead of being rude and "making" him go first, I'll just "ask" him politely to go first and then I'll owe him one switcharoo of his choice in a future hand. Is that better? What do you guys do online in situations like this?