1/3, weekend daytime, otherwise fishy, loose-passive table.

4 limpers, including Villain in early position.

Villain ($300, 70/30) is a 40yo white male who smells, he claims to have been playing for the last 35 hours, lost 2 buyins in last hour.
He is extremely aggressive postflop, and has a very low win a showdown rate, although he will NOT attempt to bluff hands with showdown value.
He does, however, call draws without adequate odds to some degree (or raise them!)

Hero ($325) raises to $25 with Js Jc on the button.
Only villain calls.

Flop ($59): 5h 4h 3s

checked to Hero, bets $30
Villain check-raises to $90

What do you do?

[Side question: what is the approximate maximum VPIP, with a 100bb buyin and 10% to $8 max rake, that is profitable for a good player on a full ring table full of average players?]

Think you can either jam it here to get it in vs smaller pockets, draws and some 5x or call and evaluate turn. If turn doesnt complete draws i think you gotta go with it.
Considering the player image you gave i dont think folding is a thing there just yet.

It's up to you -- you can either ship it in and take what's likely a slightly favorable flip now, or call, hope the turn is a non-heart 8-J or board pair, and ship it in then. I don't really want to fold against this V, so I'd probably just ship it in now.

Regarding your side question: An excellent player can probably be winning at 30/25 or so in that scenario, but a "just good" player should probably be 22/18 at the most I'd think. You just should be so tight up front that it's tough to have a good VPIP much above that.

I check this flop because villain has us crushed with the nut advantage.

Honestly, I just let this one go. Best case scenario is he has hearts, but he has every two pair combo, every set, and every straight.

Maniac can also have 66-TT, A3-A7, maybe 78, maybe 7x with bdfd, 46, 56, 57, etc. V playing 70/30 probably would open pairs bigger than ours, so I mean, I think even if A2/67/33/44/55 are all in range for V, they'll have plenty of other stuff that we're either somewhat ahead or way ahead of. If they're only going to have suited A2/67 then they have 17 combos of great hands ... and 30 combos of just 66-TT, 36 if you include 22 also. No way I'm folding here.

Just rip flop, I'm never folding anyway

He should have unsuited combos of straights and 2p as well if player description is correct... That's a good point about the 30 combos of over played 66-TT, but I villain to have 32 combos of A2 and 76 combined, all connecting 2p, so 24 combos, plus we'll just say 2 combos of 53s, so 58 combos have us beat.

I find it unlikely he has A3 as the hand has showdown value, and OP said he's not doing that.

He also should have every combo of hearts and pair + SD, so a call looks more and more reasonable to me, but ultimately I think betting the flop is the mistake. I think checking and calling turn and river clean run outs is a much better option.

I like calling his flop x/r and re-evaluating on turn. Given his aggression I think GII on flop is bad because it takes away the opportunity for him to hang himself on the turn.

If he's been showing down weak after being aggressive during the hand, then I have no problem playing for stacks on most turns. This board doesn't connect with our range at all, so this could make it even easier for V to make a play at us.

That's really interesting -- I'd think of A3 as a hand that's a pair + SD.

I don't think there's enough clean runouts -- every card 7 and lower, AKQ, and hearts could be bad for you, and you'll never know which ones. There's only 10 good cards remaining in the deck if you exclude runners (non-heart 89TJ and nothing else). So you're very likely to not get a clean run out...so what do you do then?

I think A3 is a much less likely combo for him to raise because the completed straight is the bottom straight, but yeah I guess I wouldn't be surprised if he raised it.

Your second point is exactly why I want to check, and originally said to fold...This is just a terrible board texture for us.

It is a terrible texture for us -- but our hand rates to be best at the moment against V's range, even after their raise. So we now have a new avenue of solving the "don't know which runouts we like" issue which is jam it all in!

Just because 3/4 of the turn cards could be bad for us doesn't mean they all are, and doesn't mean we can't get the money in right now. In fact, if anything it's an argument for betting the flop bigger than $30, as it's likelier to terminate the hand immediately.

You've made very strong points that have made me change my mind on what's the best action here.

Would you be more likely to x back flop or bet-fold vs a better opponent?

I'm very likely betting. I think the main thing remains that we don't like the runouts, so we're trying to terminate the hand early if possible. Obviously the downside is that we're bloating the pot, so it depends a lot on what sort of better they are -- if they're always going to show you the goods when they c/r, obviously fold to the c/r!

If they've got a nice mix of bluffs including check/call/donk lines on scare cards, then and only then could I be swayed into checking here, but checking here is turning your hand that I feel like should have around 55-60% equity against even a good V's continuing range into a hand that has like 25-30% equity, because if they bet a non-89TJ you're folding on the turn. You also may fold if the 89TJ is a heart. I don't think a V this challenging shows up at LLSNL too frequently, so you've got that going for you, which is nice!

So that all stinks -- me personally in game, I'd probably just c-bet here because I think it reduces the game a bit -- it makes it likelier that kings and queens become okay cards for us. If any 8 through K including hearts is a fine card, then we've got half the deck again, which not only means the turns don't suck, but the rivers are better too, so we can check behind the turn hopefully and now you've gotten to see the runout, I think on a runout like Q-3 you can maybe even call a 1/2 PSB on the river as a bluffcatcher against A6 of hearts or whatever.

Yeah flop bet is more than std vs this splashy guy, and otf i sigh snap ship it in. Never folding

I judged that I needed to end the hand quickly. If I folded against him here he would run over me. I shoved and he snap called.

Turn is the 8c. River is the As.

He shows 3-2hh and wins with a straight.

Lol!