The recent spate of forced mascot changes and the striking down of trademarks are based solely on claims of offensiveness of these terms of speech to certain segments of society. At its heart then this is a free-speech issue. Should our freedom of speech be limited by subjective claims of offensiveness of that speech by certain parts of our society? That is being answered in the affirmative currently and I disagree heartily.
It makes no sense to rank the nicknames in order of potential offensiveness when deciding if they should be banned or not. They shouldn't be allowed or disallowed on the highly subjective basis of offensiveness in the first place.