Full house vs. full house vs. a loose fish is definitely a cooler. That said, if he was a better player would you have played the hand differently and laid down the boat?

That's a fine hand to 3bet vs a loose fish, but like Midori I don't like squeezing with it and playing a bloated multy-way pot. If we're unlikely to get into a HU pot with the fish, i'd rather play for implied odds with our nut suit and connectivity.

Flop is very standard. Anything after that is really villain depended. I don't fault you for calling down here and I'd probably do the same if I perceive my opponent to be both thinking and capable mentally of pulling off a huge bluff. He's representing exactly one hand (99), and you have a very strong hand considering that you squeezed preflop and thus don't have many 4x or 99 in your range.

Like Midori said, the toughest spot is probably the river. On the turn, you still have a bunch of overpairs in your range, especially since he raised you so small on the flop. But on the river your range has a lot of flushes and boats.

On the other hand, he's shoving for 40% of the pot which makes it much tougher for us to fold a boat. I would usually call this in-game and to be honest, I won't spend any time torturing myself about it if he does have 99. It's a theoretically sound call, and since this spot comes up so rarely, I prefer to focus on other spots that can really increase my winrate. If you're going to torture yourself when you see the nuts then definitely fold, because most of the time that's going to happen.