stinks of a scammer.
1) Tries to get users off site and on to skype - Red flag
2) Wont (cant) sign a message from the address holding the bitcoin - Red flag.
3) Claims to be not used to forum but has been a member for over a year - Bought account? - Red flag.
If you send anything to this guy first without Escrow then you deserve to loose it.
Well I don't agree with you for point [1] & [3], as i have seen a lot of trusted deals going over skype , I don't think op has bought that account , i have been seeing him taking the same way ever since he was newbie.
I don't smell a scam in this case but i am sure that a scam will happen whoever makes a deal with OP without Escrow, what i agree with you is point [2] , genuinely OP is lying that he has 10
BTC , he has none , he just keep bumping his thread with new account.