Your edit concerns are really edge-cases. If you say someone is a murderer, and they only murdered people in minecraft... as well as in real life, they can't sue you for defamation, because that "as well as in real life" part really trumps everything else. You'd need a ridiculously specific and niche case to get a defamation suit going.

And I think even activist lefty judges will go "the pedo's future earnings potential got hurt because someone called them a pedo of slightly different circumstance? Uhh... Yeah, no damages were done, their reputation was already gone."