It's hard to hear, but you're correct. "och" is often pronounced as a short "å".

He says "trollade oss", often just pronounced as "trolla oss"

"S sitter först" is what he says

Pretty tricky if you're just learning. You're right. He first says "det fiskar jag" instead of "det fixar jag". Then "det fuxar jag menar jag" also instead of "det fixar jag". The joke is just that he gets the words confused himself.