1) I guess it could be mixed. And if i'm honest I'm not so certain how this spot is supposed to play. My intuition thought that we win plenty vs air that has stabbed on the river A or low ev check downs such as weak pairs and hands like 56.

2) This hand looks close. We have nut gutter so just significant implied odds. I agree it's close vs this size. I would fold without the 4d as I do think that inch of additional equity may render this +EV. I think QTo no diamond is a fold and calling with the diamond. You sum up my main reasons for the peel which are 'we have BD diamonds, and a gutter, and suppose can use it to balance our range, as if we fold this where are we drawing bluffs from. For me this was a big argument as if we overcall here our range looks pretty strong and we can anticipate BU to not stab liberally on the turn into a shortstacked recreational and an overcaller so we will get to see a river at a high frequency.

26min btn open 3.5bb and hero 3bet A9o 14bb saying vs larger sizing we have more incentive to 3 bet given the worse price to call. How do you deal with this at lower stakes where recs seem to bet their hand strength i.e larger open means stronger hands?

When someone opens a bigger sizing they are risking more money to win 1.5BB's. So our defense frequency goes down. A bigger open sizing will also push our own strategy towards a 3-bet or fold one (obv not a full one in the BB).
If at lower stakes people are splitting their range considering the strength of their hand that would mean that against a bigger open sizing your 3-bets will be overcalled or 4-bet. 3-bet lineair and cut down on bluffs.

In the video I see 2.5 open btn and sb snd 2.2 from HJ \ LJ I was thinking this would be opposite. Where LJ & HJ we have tighter range and want more value.

This is often the logic people have. We have a stronger range EP so we want more money in the pot. But the opposite is actually true. We have a stronger range so we want to incentive other players to play a weaker range against us. In the later positions we have a wide weaker range and want to discourage BB to call.
At lower stakes I would still open steal positions small because population is still overfolding their BB.

1) I generally open 2.5x in the SB just because it's what I had solved at 200z.

2) If a fish is opening bigger when they have a bigger hand then you just exploit them by folding more preflop and not giving them action. If really depends on which range they are using. if they are opening a normal range big then you just have to 3 bet more liberally.

3) You can an use whichever sizes you wish as long as you are using correct ranges for said sizings.

4) This was a mistake for 500z rake structures. BBvHJ K2dd is a pure call. I don't have the exact ranges solved for 500z stars rake structure but I would assume 54o is mixed BBvBU 2.5x and 65o+ pure call. Ranges should tighten up at lower stakes because of rake but postflop edges get bigger so could argue that you can make that ev differential up postflop.

Henry Lister or lIlCitanul against larger btn opens where you view recs to have more of their north pole range, would you size way up with your 3 bets? Say $3.5 to $15 with like QQ+ because rec likes his hand and you wanna push your equity preflop, then vs like 2.5bb open just stick to 10-12bb 3bet from SB? Any opinion on using smaller 8-9bb sizing sb vs btn with standard 15% or so of hands to keep btn range some what wide with hands we may dominate?

I had a hand other day where guy was limping or raising 2.5x on btn from small sample. Now I get AKo in SB and he makes it 3.5x on btn. Thinking he has a strong hand I decide to just call rather than force a flip. Turned out he has 64s. Postflop was 642ddd i had AdKx and we got the money in. Ended up chopping. Then after watching this video.

Based on the A9o 3bet I tried and 3 bet more with KJo, A8s, QJo etc vs larger opens and ended up just donating a couple buy-in. Confirming 90% of the time larger opens are heavily weighted towards value and I should over fold or flat call and play more postflop.

This is not something I have ever constructed myself however I would assume calling some middling pocket pairs, suited connectors and suited broadways make a ton of sense here. Realistically it could be anything that is strong enough to continue that does not wish to play as a value 3 bet or have stellar blockers to 3 bet bluff.

Generally I would just bet my flushes but decided to just randomise here sometimes. I think if you never check back a flush here then you're opening yourself up to get potentially exploited on a brick river if your opponent introduces a significantly sized overbet strategy. So it's sacrificing some EV on this exact hand to yield greater EV over the rest of my entire strategy with other hands (as my opponent now get countered if he tries to exploit me by attacking me with a check raise on the river).

Recent video with Steve Paul "getting back in shape" he uses GTO trainer. GTO trainer is checking back quite a few middling flushes. I think betting all your nut and 2nd nut flushes and low flushes probably good with a mix of your NF blocker as bluffs. GTO trainer was checking back nearly half its flushes.

Solved preflop strategies would be referring to MonkerSolver solved strategies for 6max with 200zoom rake structure.

It's in starshelper.