I notice you did not open your thread and ask someone to verify your address and tag hacker so he can not use your accounts on a way he is using it now. Also mods can ban your account if you prove that you are owner, and signed message is good proof for that.
Lucius, I'm not sure I follow your suggestion. Am I approaching this in the wrong way? What should I do next in your opinion? Here's a timeline of my actions:
You did everything as stated in
"Recovering hacked accounts or accounts with lost passwords", but your account should be tagged by DT member and banned by mod so hacker can not do more damage to your account. It is quite logical that the account is completely blocked until the moment it is returned to the right owner, in this case to you.