Those are all adjectives. It is not used interchangeably as a noun.

If one is derogatory then the other should be as well. Try it out with some more universally accepted derogatory nouns to see my point. Thinking about it, when applied as an adjective most terms sound even worse.

I honestly can't think of any that aren't just repurposed adjectives rather than true nouns or vice versa.

As an adjective you mean. Which is different.