No collateral, Yes I am stupid, please, this is not the point here!
I would like to know any piece of information on him that I can't get from his profile here.
Whatever info you find on the account creator is probably not going to be the same person that scammed you. I have been seeing a few people selling older senior and hero member accounts. It could easily be one of those situations (or hacked account as another person stated).
Either way, sounds rough.
I don't believe this is the case,
He had a newsletter https://bitcointalksearch.org/topic/arepos-weekly-newsletter-discussion-and-analysis-509527
And he used the email written in his profile to send the news letters.
Also, If you follow the bitcoins I sent him it seems they ended up in an exchange or something like that
and not stored in some private persons wallet.
May be I'm naive (again) but I think that something may have happen to him and the coins are stuck in one of the exchanges
and all I need to do is find out where they are.
Have you tried getting his IP address through gmail? It might give you some more information about his identity.