Uh...
OK. First of all, this is my first time seeing that "tr" word. Had no idea what it means. Maybe it's a new term or maybe I'm just not American enough to catch up and learn these new words.
shrugs Maybe the mods should have given a warning instead of a 3-day ban right away. It does seem excessive. As for OP, if the podcast you listen to uses this kind of questionable vocab, maybe it's not something worth listening to? Also, I didn't get what was anti-trans about that manga or chapter, either.
Second of all, asking for a list of words Americans consider offensive is a fool's errand. Any word can be considered offensive when used in different context, situation, and time. A word that means nothing today can be forbidden tomorrow. Some people are extra sensitive to basically everything, some less so. Your list can be as long as an entire dictionary. For example: the word trap can be used to describe a crossdressing boy. It didn't carry any negative meaning, until some people gave themselves the right to decide for everyone that it's an offensive word and want to ban it. How long before these words are banned as well?
Femboy, transformers, Tran (Vietnamese last name), trench, futanari, crossdressers, tram, ningen, nigerun dayo, niggardly, nagging, Niger, nickel, etc.
Idiot A hijacks a word to use it in a derogatory way. Idiot B then declares that word a taboo and wants to ban it. The sensible thing to do is to ignore Idiot A and tell Idiot B to stfu as well. The US do not have the authority to make the rest of the world bow down to them. What happens when you have a word that Americans consider to be offensive but Canadians don't? If you ban a word, trolls will just invent a new one to circumvent the ban. Or they hijack another word and you ban that word, too, and they move on to another.
I suggest that we don't ban words, unless they can only used in a derogatory way, but see what kind of context a word is used in, or if the point of a post is really just to be spreading hate.