I second Orin's suggestion that it is worth reading The Etiquette of Equality, by Ben Eidelson. I saw the paper presented at a workshop last year and have thought about it regularly since then. A couple of additional thoughts:
The fact that there is an etiquette norm (or contested etiquette norm) against using particular words or making particular analogies is for me not the end of the inquiry. Sometimes there are etiquette norms that we can be justified in violating—indeed, we might even think it important to violate and try to undermine them if they are too nefarious. Maybe we refuse to bow to a foreign prince, or refuse to obey gendered clothing norms.
Or maybe we insist on exercising our right to free speech, even in cases where it is offensive, precisely because of the importance of that right to free speech. Or maybe not. The etiquette analysis helps us see why exercising that right is costly, and helps us process a negative reaction, but it doesn't tell us which etiquette norms we should have or when we are morally justified in violating them.
