then when she turns you down

The only she turned him down was, if they run away from the attack her sister and other villagers would die.

He was AWFUL in the Royal Selection episode

Agree with you. He was being awful. But other people were being openly racist against her and Emilia wasn't that bold in season 1. So you cannot expect subaru to stay quiet and ignore that. But yeah his method were wrong but his intention wasn't.

only did he show up with ANOTHER Royal Candidate Priscilla was a reason too. She wanted to create commotion there.

Also, when he was telling Emilia "You owe me more than you could possibly pay" he was a creepy psycho.

Again agree with you. He was acting psycho but people throw tantrum and argue in normal life too.and he can't even talk about his situation without getting his organ churned up.

he exaggerated his 'craziness' which resulted in a bunch of deaths

Even he was not crazy, petelgeuse and white whale would still attack. It has nothing to do with his situation.

immediately snapped out of it as soon as Rem died magically.

Honestly that scene made sense. Petelgeuse forced his mind open.

Also, to die and go back to the same spot standing up mid conversation, and he didn't realize he was resetting really was irritating,

That only happened on his first deaths.

I agree with subaru being awful in some parts. But other characters like(puck, rem, ram) has done way worse things to him. but people generally try to ignore that.

Sorry for the long answer.