Crummy but what can we do? it's not out car. he can drive it however the wants. We could counter his votes and leave a comment the author that it is nothing personal but that may lead to serious drama. something I would avoid.
Has the account made any withdrawals that match another user?
I don't even bother to search and waste my time. Only dumb people leave such evidence.
Smart knows how to hide even smallest traces, because blockchain keeps all "burned in stone"
That is a very good question. I'm not sure how to find out.