Bet sizing.

100 is too high, since he'd fold everything except Ax. You want him to continue with a much wider range. Put in ~60 and jam on the river.

Here's how I'd approach it:

Our goal is to get it all in with as many of his hands as possible.

If we think he's going to get sticky with Ax, then we can probably expect Ax to call a third barrel. We can bet a more modest $75, and that leaves us with a pot of $236 with $160 behind an SPR of 0.68. It's pretty reasonable to expect a good chunk of Ax to call that down from a V with stationy tendencies. So is it necessary to pile it in on the turn vs Ax? No. We expect to get it all in anyway. I'd just want the SPR to be well below 1x.

Is V going to get sticky with 7x or 3x? I don't think those are calling anything when a second overcard comes out unless they also have a club draw. That portion of his range probably gives up if we breathe on the pot. So there's no reason to target it.

Gutshots: If V was floating flow with 65, 54, 42 - is he going to call a bet on the turn? Not $100. Probably not even $75. We'd have to size way down to something like $30-$40. But then that impairs our ability to jam vs his Ax holdings and those are not paying anything if they brick river. So I wouldn't target that portion of his range.

Random 2p: A7, 73 - you said he calls almost anything pre, but for the same reason as Ax, we're going to get it all in on the river and he might jam turn. So any size is good vs these.

Flush draws: Not sure how many BDFD he's floating on the flop, probably the most obvious is a hand like 7xcc, maybe 65cc. Vs a hand like K7cc he has 25% equity, and that goes up to about 27% if he has 65cc. We want to bet big enough to give him a bad price, but not so big as to fold those hands out. If we bet around $75, he requires about 32% equity to make the call, and he doesn't have it with his FDs. But I'd expect many players to call the $75 with a FD. I think $50 would be a mistake because we're giving him about the right odds to continue with FDs.

So the portions of Vs range I'd want to target are FDs and Ax+. We'd have to size down too much to capture value from 7x, gutshots or middle pps, and that would surrender value from FDs and Ax holdings. We have to bet at least $75 to give FDs a bad price, and we want to set up set up an SPR decently below 1x on the river so that Ax can't get away.

Given stack depth, $75 achieves all those goals. It gives FDs a bad price but can be expected to be called by FDs and Ax at a reasonable frequency and sets up an SPR below 0.7x which should get us paid off on the river jam by Ax. If we were deeper, then maybe we want to size up and only target the Ax+. Say we started $400-$500 deep, then I think we want to overbet so that we can jam river and expect to get called by bigger Ax like AK/AQ/AT. But at $300, a $75 bet sets up a small SPR where we should get paid on the river frequently enough.

For that reason, I think a size around $75 is probably the sweet spot against most players. If we think V will call $100 with a FD, then by all means size up vs him. But that's my general thought process when coming up with a size.

How often was the straddle on? If this guy is calling really wide then I'd probably open 5x.

If you went 5x then you could probably go 2 streets, but when the pot is only 46 you'd need to bet pot on the flop and 2x jam on the turn which might let him off the hook with some of his weaker Ax hands. If you go something like 30-70-180 that probably gets the money in smoothly. There aren't really any draws so you're squarely targeting an Ace. Against this opponent it's entirely reasonable to assume you have the best hand often enough to justify getting it all in. Obviously you will sometimes value own yourself (I'm assuming you didn't make Aces up on the turn). But with no draws, it seems that there's no real major benefit to getting it in over two streets

I like flop but probably 80 is good on turn. Don't need to over bet. I think pre should be 25 minimum.

Grunch:

PRE - Seems fine. If the BTN is calling with ATC, I might raise bigger, and keep increasing my size until we find his pain threshold.

It's not that we want him to fold, we just want to know how big a raise he'll call. We're only playing $300 eff. We can just raise big with our best hands and value-town him on flops and turns. This could be a two-street hand, but we need to start by raising bigger pre, and c-betting big when we smash the flop.

FLOP - I don't like the 1/2 pot size. Either check and see if he wants to stab at it, or over-bet.

If we check and he checks back, I'll start betting big on most turns. If he bets, I'll either call or raise depending on the size, but mostly I just flat call until I see if they have sizing tells. If we check-call flop and the turn checks through, I'll bomb the river.

TURN - As played to this point, and against most low-stakes recs, I'd size way up and over-bet, targeting all their AX combos. Against this V, I could see arguments for betting small, betting big, and even going for a check-raise.

The thing about this V type is that they tend to play so passively that it's hard to range them using the same bet sizes we'd use against the rest of the population. He could have AJ beat on the flop, and we'd never know it until showdown.

So, when V won't 3B pre or fast-play on dry / static flops, we need to manipulate the pot size and find ways to get them to tip their hand strength.

If we check turn, he'll bet his AX for value and protection. If we bet small, he'll raise his sets. If we bet big, he'll either call or fold, and if he calls we'll be guessing what his range is on the river.