lol......'correct' R/T depends on where you're from and the sandbox you're playing in. Or in which you're playing for the more pedantic. If it consistently works it's correct.
Everyone gets along just fine. If you're a peckerwood you'll be appropriately treated as such no matter where you're from. What comes back at you depends on what you put out which is a person not a geographic thing.
Probably the most important thing to remember about Americans is you'll find some of them to be of the older breed who really fight back (and don't just whinge about their lot although some of them do just that). Everyone has their quarks.