Well then...
Not familiar with the "r slur" or the "m slur"
Well they have been called that for a long time and I wouldn't call it a slur. It is just a mistake because columbus thought he was in India and the name just stuck.
Eskimo is not really a slur either, it is actually a name. The Eskimo people speak quite a lot of languages, so one language could say it means that, but another something different.