its fake dude if satoshi is still alive and make a return he wouldn't do it this way. Also he would be smart to know that nobody is going to believe him without a signed key.
No one has his public key... he has never signed anything!!! unless you know this guy, you will never ever get a provable signed msg from mr nakamoto
Not so sure about this, seems to me I've seen something signed. If he really never signed anything, it would be odd for him to start signing now.