Hello,
read that i have so far that fits to this situation is, that he cbetet very small with air, so maybe you can use that information for his turn betsize.

Would you even call the gutshot + overcard here and would you make a big bet first in on the Ace river?
Do the implied odds justify the flop+turn calls or is this an easy fold?

I am folding right on the flop. You do not even have any kind of bd fd and I pressume, that villain will bluff ton of turns and rivers.

raise pre

i fold flop

pretty easy check pre since we have such significant chip lead vs presumed fish with a hand that does poorly postflop with little reads on villain's postflop tendencies. against regs it's ok (and mostly standard) to raise q4s and most suited hands but against fish and/or readless it's a no brainer check pre.

as played, fold flop, you're essentially calling for pot odds to hit straight and Q for 7 outs. we need really really amazing pot odds to call here for implied odds which you're not getting. calling also puts us in really bad spots where you can't do anything but check/fold if missed. also you need some super strong read and dynamics to c/c turn here which i'm not sure we have.

You are joking, right?

As for the hand - fold to the flop raise, pre iso is not a bad option.

yes if that sentence is taken out of context (mostly). but i said:

So your reasons being - significant chip lead and playing a fish?

I would put it another way - when I think what to do I usually take into account the stack depth in big blinds and reads (or if there aren't any use readless strategy) and then decide what to do. Passing spots in hypers because of chip lead or playing a rec (against whom we might happen every now and then to have post flop skill advantage) is simply wrong.

What was his vpip in sb? You can even jam pre, and if you want to do a nominal raise instead remember you want to be jamming turns (given the right runouts), so size your bets accordingly

You can discuss about the preflop play but he made much bigger mistakes on the other streets.

some people will agree with the below, others disagree but here it is:

you should have a significantly different mindset when playing against fish vs. solid reg
- against a solid reg who won't make many mistakes, you need to be taking every +ev spot however marginal they are. that includes iso with Q4s which as i said previously is standard vs regs.
- against a fish who has enormous leaks, there's just no need to push for those very marginal +ev spots.

this is from both speaking with fish crushers at mid/high stakes and personal experience at midstakes. i won't go into detail on people's exact strat but a lot of the fish crushers are doing things that are not 'public/common knowledge' yet they achieve 4%+ ev roi

Why is raising q4s std vs regs??

Its a very mediocre hand that does better vs his overall limprange than vs his limpcallrange ,has decent equity against his limpjamrange, plays better in a limped pot than in a 3bet pot and we have the option of seeing a flop for free which already gives us a good expectation, so i think raising doesnt make much sense?

I would check pre and checkcall on the flop. The flop hits our range harder than his so its decent to have a wide leading range because he should check back quite often, but this hand i think is better to checkcall, we have some showdownvalue and it sucks if we lead and he raises. As played on the river his line doesnt make a ton of sense with a 6 or a 3 so i wouldnt even hate calling it off tbh but i guess folding is the std option without more reads.

About the fish vs regs point: I think the main thing in this spot is not that we do not want to take a marginal +ev spot vs fish but that the spot is simply not +ev, even if raising this hand would be good vs regs, fish play worse in limped pot so the ev of checking will be higher thus harder to beat. (They play worse in raised pots aswell obv but the difference in ev is arguably higher in limped pots assuming same starting ranges).

I would also fold the flop but i'm not raising this pre, I think our hand does well against a limping range no ?

I would check back this hand too preflop vs fish.
On the flop I want to know how often he limp/cbets.
If hus limp/cbet is high I want to x/r flop if it is low I want to lead and barrel most of the time.
As played a fold is best after he raises your leadbet.