Armchair, my sincere thanks for your efforts. I appreciate ya, you take this seriously and do a great job. Thank you.
My 2 cents is that we gotta let some offense be made. I assume we're mostly adults? We know who's trying to wind people up. For example, Netserk and his Bambi avatar. Funny in a way, and obvious light trolling. Creative. Also easily ignored. If a person can't take that, maybe the internet isn't for you.
I know you can't have a wild west, but there's no line on nicknames that's going to make defensible sense. Someone repeatedly using nicknames and successfully winding people up? That's covered under trolling. People going on and on and on with personal attacks? Covered. Warn then ban. The occasional use of a derogatory nickname? The repeated use of a derogatory nickname in the context of a reasonable, intelligent post? Let's be grownups and let it pass.
I ask we err on the side of free expression, and stick with the rules we have against trolling and personal attacks. The current rules cover all the problems IMO. We have to allow offense, let's not make this place a safe space. GenX and previous generations had this one right. Sticks and stones and all that. We don't have the right not to be offended, and you'll kill yourself trying to define and justify what speech is allowed.
That said, you're doing the work. Your call. I'm just suggesting it'll be less work and more fun if we can all grow a bit thicker skin and let the current rules cover the truly disruptive behavior.