Flopped a Full House, Ace on the River v. PFR

Does he look visibly frustrated?

call and probably instantly just to tilt him a little extra when he's bluffing.

Wazz is right, snap call > regular call.

I did snap call so as to not accidentally slowroll. He of course had AAxx (with hearts). I guess I could beat KKxx with spades or hearts...

yeah, you probably need to call that, no other way.

but, on a side note, i would have led out on the flop.
nobody is betting on that flop, aces or kings will happily take a free card, but call your bet. you could then charge max on the turn, and he either folds, or makes a really bad call with just an overpair.

also, your second boat is really vulnerable to any 9,10,J,K or A (all could make a higher boat) ... that's why i like to lead out.

What sizing do you like on the flop: 150, 225, or 450? What about the turn after betting the flop?

i like 1/3, so 150ish seems fine, may be even 130.
you charge enough to have an overpair make a bad call, a weaker 8 will call, and it also can look like a bad bluff/steal attempt ... depending on players/action the occasional 9-10-J draw might also call, drawing dead against you.

turn bet depends on how many calls you get, but i'd go much higher if no overcard to the 8 shows up, like 3/4 pot.

again, all up to player tendencies and the action before that, you gotta factor that in.

I think you need to bet the flop and turn. Don't let AA and KK set the river cheaply like this.

Is check-raising the flop overplaying my hand?

Kinda unless you'd do the same with a bunch of bluffs

don't forget, CR requires that someone bets first ... on this kind of board in a multiway pot i'd say that's probably not very often going to happen

I don't know what I was trying to do. I just transitioned from hold'em and checked out of habit.

in a heads-up situation a check would be totally fine, someone who 3bet kings or aces preflop will almost always take a stab at this flop, and you can get your CR in.

Multiway (as described in your scenario) the likelihood of someone betting is very small, so with your strong holding (strong now) you just give a free card, don't get value, and invite to be outdrawn.

also: let's say someone is out there who has an 8 ... he's probably also not betting, but will definitely call a bet from you, being in very bad shape or in case he has no overcards to your Q he is drawing dead.