If CSW had no ability to sign real messages then he simply would have left his proof at duping individuals and having them vouch for him. It would have certainly worked well enough to drum up some investors and run off with their money.
So if he had some access to the keys does that make him Satoshi or part of a Satoshi team? Personally I think the real Satoshi was happy to use him and sign some messages for him but baulked at signing public proof. It's pretty similar in outcome to having a trust that cooperated with him and then didn't but much simpler.
He'd have to have a live link to satoshi is all. I don't buy that he had the actual key and then either forgot or refused to use it for the sake of the 'trust'
So if he had some access to the keys does that make him Satoshi or part of a Satoshi team? Personally I think the real Satoshi was happy to use him and sign some messages for him but baulked at signing public proof. It's pretty similar in outcome to having a trust that cooperated with him and then didn't but much simpler.