I agree, we should focus on the Essentials - Office 365 integration. The thread you posted is the exact same error that I have on my Server 2012 Essentials server. Exactly the same. I've been monitoring the thread just in case someone would have a solution but nothing so far.
The DC roll is installed on the Windows 2012 Essentials server. The Windows 2008 R2 server was just a test-server to see if we could use the DirSync tool as a workaround because I could not find a solution the problems on the Essentials server.
To be honest, I would not prefer to ask in that different forum. I don't want to spend another month with forum who are asking the same things over and over again. I believe that's just waste of time, but if you are running out of options, I understand your statement. There is Thomas as well struggling with the same issue so this have to be solved somehow.
I'd like to know why DirSync is not recommended to install on Essentials server?
Best Regards
Jopi