I suggest using the power of your free speech to walk up in person too anyone of color and using any of those words to their face and see how your "free speech" goes.
Furthermore, a little reasearch on what "free speech" means and doesn't mean might be in order.
What I find interesting is that so many people seem to want to stand up on the side of bigotry and demand their "right" to be a bigot and use bigoted language. I'm not sure that's really a great look.
Technically, one of the things that makes it worse - some of the folks I used to work with still had MR as their official medical diagnosis - less than a decade ago, and since most of them were young enough to probably be still alive, they still have it.