Sorry you have had such a bad first impression..
Is the ipv6 turned on? This was an after thought as they seem to have released both firmware and utility and woken up after the event to the fact they actually needed ipv6 on to manage it.
Otherwise I don't see what you are using to connect to the TC from the iMac.. is it wired or wireless??
Can I suggest you do the setup again.
This time use ethernet to the TC.. in full isolation from the network. And do the setup manually.
You may need to factory reset again.. sorry about that .. and start over.. only the Mac plugged into the TC.. nothing else.
You may need further help just post where you get up to and we can sort out what is happening from there.
This often works easier at the start from the airport utility in iphone or ipad if you have one.