Who has more flushes?

The asian guy usually.

If the idiots are playing any flushed hand, the called is more prone to have them. If they're calling with 93h and nobody is opening with them then the calling range has more flushes.

How do adjust? I'd get in pots with any suited ace. Raise larger so you get paid more when idiot with bad hand hits nothing on a rainbow board. Tread lightly if the board is very connected.

Another strategy is try to pick a table with fewer idiots. Most of them won't be still playing in a few months.

Being aware of the sheer number of flushes can matter, but not in this case. The SPR is 1, and flopped flushes are a super small portion of each of your ranges, due to it being a 4-bet pot and two broadway cards being on the flop. The only flopped flush you each can/should have at full frequency is AKdd, then it's all preflop bluff hands (A5/A4/Kx of diamonds) for you and loose 3-bet/peels for him (AT/KT of diamonds main culprits among others).

I'm probably giving up my AKo no diamond on flop

(Don’t do this.)

Open bigger over a limp. Make it $20.

Don't 4B to 30% of starting stack. Either flat call or jam.

His $50 3B over a limp and your $15 raise is BS. I just jam on him pre, and see how much he likes his hand. If he calls and flops it, c'est la vie.

Forgot to answer the questions at the bottom of the OP:

1. Assuming the 4B was for a reasonable size (and yours wasn't - it was too small), the only flushes either of you should have on this flop in a 4B pot would be AKdd, and maybe ATdd or A5dd.

Hard to say who has more flushes in a 4B pot, the CO 4B'er or the SB 3B-caller. It depends on whether or not you 4B all your AKdd/ATdd/A5dd pre, and whether or not he ever 5B jams AKdd or flat calls with either ATs or A5s.

If I'm V, I don't think I'm giving you very many flushes, when I think you'd be more likely to just jam AKdd, and I'm not sure if you'd 4B ATdd/A5dd for 30% of your starting stack instead of jamming for max fold equity.

Then again, since you only 4B to $120, and V only had to call off another $65, maybe he shows up with ATdd and A5dd more often than he should if you'd bet bigger, and perhaps even has KTdd in his range.

Also, I think I'd give the SB more flushes than if he'd 3B-called out of the BB. The SB is incentivized to get after it more than the BB.

2. It's hard to flop a flush. The adjustments we should be making here are:

A - Raise bigger pre ($20, minimum, not $15).

B - Either flat call the SB 3B pre, or 4B bigger. Here, when SB goes less than 4x, over a limp, a $15 open, and a flat call, I'd be 4B-jamming all day, at $400 eff to start. We don't mind if he folds and we take it down pre with AKo.

C - Check back this monotone flop. Yes, I realize it's a 4B pot and we should be c-betting almost always, but I wouldn't here, at 1 SPR, and no diamond in our hand.

This is a spot where blockers and un-blockers become more important. We unblock top and middle set, his flushes, his 2P, and his combos of AK with one diamond. We block the hand that he can have that might have called the 4B, but would fold if we c-bet the flop, combos like KJss, KTss, AJhh, and AThh.

I don't care who has more flushes. I would not 4! AK at 1/3 without strong reads even though it is GTO and standard at like 5/10. Your 4! sizing puts you in difficult positions on many flops. I do not like the small bet on the extremely wet flop. I would call the river. Can't fold the nut straight. He shouldn't have that many flushes.

dont 4b pre and dont bet the flop.

Villain's preflop range should not be wide at all. 1/3 players may call with any suited cards but 3! maybe KK+.

For the turn push, I would be pretty happy, because if he 3! JJ+/AK, that is all sets, over pairs, and straights. He can also have the nut flush draw with a pair if he has like AQo. You could run into a flush, but it isn't that likely.

So you want to pick a table with fewer idiots?

Your are the most excellent of the advicers!

Yup. It's far easier for a skilled player to beat someone who isn't a moron.

In general (for the 666th time) go watch the _free_ Alex Miller videos on montone flops from his live cash course.
tl;dr With sane ranges for both players nobody is inherently ahead because both players have closer to even suited combos, and on the flop esp. we mostly want to put money in with flushes, big flush draws and sets (but it's like 2 hours of free videos, so don't trust drunk me just go watch them).

Pre:
With position I think call is viable pre. ... if you think V has a fold button and is getting out of line I don't mind a shove either.
V would have to be v. good to consider the size you picked (and even then I'm not sure what you are supposed to do if he 5bet shoves).

Flop:
In a 4bet pot at 100bb-ish at live 1-3 it's not really a general spot, but I'd start with not range betting $50 (20% pot) on QJx monotone with no flush card. On the turn he doesn't seem to care about AK, so I'd be more than a little worried about AK with a diamond which has you crushed ... but I guess you have to call it off and pray he has AAd/KKd/QQ/JJ or something.

Result:

Love the 4-bet pre against this guy and others with the squeezer gene. Like others said, 4-bet shoving is probably much better. I would still induce with AKs though.

He has more flushes than you do but it doesn't matter because you're basically sitting back and laughing at him on this turn card at this SPR. It only gets interesting with AA-KK, AQ no diamond. Then you just have to determine if he has enough bluffs like what he showed up with.