As for me, at the ripe young age of fifty-four, I've never met a single person who had any pejorative thing to say about any of the various Nations or their members,
I have. You haven't been to the Dakotas much. It's usually triggered by frustration with crime, drugs, alcohol, and various resulting bad behavior near reservations. Which has its roots in poverty and a lack if self-worth. "Redskin" is not the term usually used, that part is correct.
As far as your commentary about the bad idea of making politically incorrect things illegal to say, the whole point of the First Amendment would be for naught if it weren't there to protect speech that's unpopular.
Apparently some guy was arrested for "disturbing the peace" here in Colorado a while back with the only evidence presented that he said the F-bomb loudly in a crowd and some zealous cop heard it.
His lawyer wrote a six page dissertation on why the F-bomb was protected speech and won his case. The dissertation has been quoted successfully by numerous trial lawyers since then in CO and none have lost a 1st Amendment only case, since then.
Which is why every cop in CO has been taught carefully to state that "other people showed fear" in arrest reports for "disturbing the peace" or "disorderly conduct" now, even if they arrested for someone shouting obscenities, since the only way that charge can stand now under Colorado law is by someone feeling scared/threatened by said "crusty" speech. That's our State's litmus test on those.
It'll cost you a lot of money to exonerate yourself, if it's your word against the cop that you "scared" someone. And with everyone scared of their own shadows these days and acting like teenage girls, expect continued abuse by law enforcement when they're too lazy to look up a real statute you're violating.
If one had the time and money and had simply had a verbal disagreement that ended up in Court, I can't imagine anything more fun than saying, "I most certainly was not acting disorderly, Your Honor. I was fully rational and behaving in a very orderly fashion when I told the other gentleman to 'F off'."
Anyway apparently amongst local attorneys it's known as the "F Motion". I'd love to read it.