What I don't like about our time is that it's interesting in some baroque way. Lots of gruesome shit happens, Barry Lyndons occasionally float up, but in general it seems boring and depressing.
I don't think this guy is Satoshi but no Bitcoin wallets known to belong to Satoshi have been active since their initial transactions. I think it's likely that the keys for those wallets have been lost. So I don't think the inability to sign these messages proves that he's not Satoshi, the fraud does though.