Couple'o'things for OP: first of all, don't kid yourself, you don't have a thick skin. You may honestly believe so; deriving from your posts' lexicon, your skin may be thick for the cultural discourse you're in but it's not Hafen (or, honestly, "the internet") thick. Try to live with a fact that there are people here who spam your PM with "nigger" and you can do nothing but ignore this sad fact.
Secondly, as you get gradually more frustrated, obnoxious and generalising, the notion that you retroactively probably deserve the ban (and all the consecutive messing with you that followed) grows in my mind.
And, lastly, since you've decided to quit, good riddance. This will probably go down in history as "that time when Snail made a special snowflake ragequit via realm chat".
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As for the matter of Critique and ideas from the original post, the only thing left to do is reiterate: realm chats are not "a global chat", therefore they are governed and moderated at will of the owner. Their house, their rules, nothing is supposed to be "fair".
Global chat feature, arguably, may be a good idea (although I personally don't see the necessity), go make a Suggestion thread without all the drama. Oh wait, you've quit.