Do we believe him?

Well, I think that we can call if we have read - if u say he is aggressive and loose then we can call. Anyway to unknown player I would fold. And yes I think that your flop bet is same as checking.

he did not say that oponent is agresive, so I like folding river. It multiway pot, draws completed, should often be strong.

Edit:
Just noticed stats 77/30

so there is a chance that he is agro, so call maybe would not be bad, but still he can be postflop more passive and still 4way and draws completed, so I still like folding more vs this sizing.

against a whale I think we can bluff catch here OTR, against a different and tighter opponent I would x/f

Cheers for the feedback. Like you say normally I wouldn't have gotten that far, but I think with the read it worked ok. Would have felt like a wally if it was wrong though

No need to bluffcatch if you do not have observation that he x flop and turn and pot bluffs river.

I would have bet flop bigger.

I bet more flop for protection/collect dad money, or i check flop for bluff catcher bu, as played without clubs in hand is a sick call: oppo can overplay kx

Your feeling vs villain is fundamental:
"Villian had been playing very loose and had lost quiet a few pots"
I think that in multhway he doesnt call random, i mistake nh

Bet 2/3 otf and give up

On the flop you do not bet less than half pot (unless Sit and Go or Tournament) otherwise you give great odds to your opponents to call you. So your bet is ineffective here, you might as well check.

At micro stakes, call river bets more (if you are a good player, tight). Not here, in general.

That 18% flop bet serves no purpose. River bet too big to call. You'll not have 50% success rate, especially 3-ways.