It always feels like the mods are just disagreeing with you. The opposite side feels the same way.
I described your comment as being a jerk because mariedm asked for copywriting suggestions, specifically in the context of being a non-native speaker, and you responded with a polemical smackdown. That's not good-faith discussion.
I heard this word used in a meeting just this week, and it was quite shocking. I almost just got up and walked out. It's sort of like calling someone a "deplorable"--if you want to get people on your side, it's not a word to use.
It is acceptable in native English. I think your target audience will understand. However, some people not in your target audience will get offended so it's up to you as to whether that's a problem for you.
Nonsense. About the only thing that's odd is the unnecessary ellipsis. But otherwise it's perfectly reasonable English. And expresses a perfectly reasonable idea.