I did the same removed the UG server from the domain and now i am able to open the console no TMG storage problems. Beats me what UAG doing when deployed wihtinn a domain.
I am trying to get the uag server back in the domain. Tip: check your TMG logging. You have to configure to authentication server settings and you have to allow ds services (port 445)
edit: managed to get the uag server back in the domain. Be sure to allow LDAP fom localhost to your dc, edit the policy rule for tcp 445 to allow to dc, also allow kerberos from local host to dc otherwise you cannot logon to the uag server, with domain creds.
This cannot be the way to do this but , for the moment it worked.
edit: Product still working without problems.