The second one sort of depends on the player. I've had a few players that have made absolutely ridiculous characters but played them very well and it was a good experience.
The first one is a strong no. I've never seen anyone who does a broken meta build do anything beyond ruin everyone's time and complain (or quit) if the DM reins them in at all.
For some reason any time I have ever brought up playing a centaur, every DM always shoots it down either saying its a serious campaign or it doesn't fit the vibe.
I'm not sure what everyone has against them so I've assumed they're either broken somehow or that someone will attempt the centaur stacking shenanigans.
This is definitely going in the book.
I'm in the same boat. I also got rulebooks for Pathfinder 2E + Mutants and Masterminds in case I wanted to mix it up.
Now they all have a neat little spot on the shelf to collect dust.