I consider myself pretty tolerant to most idiosyncrasies to be honest. I started hosting in August of 2019.
However, a couple things drive me up the wall. I run a self dealt game, and there is no dedicated dealer. That said, I've got a couple players who won't stop nagging about "big blind shuffle". That's the system I like, that's what I will always use. I still get players who whine and literally bitch about it. It's not complicated and I get agitated with players who keep complaining about it throughout the game.
The only other thing that makes me bonkers, is seeing some players abuse the chips. Rubbing them together and throwing them in pots rather disrespectfully. I've never said anything, but boy oh boy, a couple times, I've had to bite my tongue. I guess I feel like it's not their fault I throw out Paulsons to use. It's a tough one, and I don't want to start losing players as I'm trying to grow my game, but sooner or later, not sure I can remain quiet.
Otherwise, I consider myself pretty relaxed and easy going about all the other stuff.