I don't care about the TM issue, I don't even care about the free speech issue. I'd actually prefer that the gov't have nothing to do with any of this.

It's a decency issue. He should change it because it is offensive. He should do it because he's the person in the best position to do so.

And, I do think you can rank offensiveness. Particularly you can rank things as offensive (eg, Washington Redskins) and not offensive (eg, every other mascot on your original list).