For those that might be interested in setting up Lync 2013 to be able to call out to the PSTN via a 7100 and to be able to call back and forth from a Lync client to Adtran phone, I posted a walkthrough on our company blog. It was actually quite simple and didn't take much on the Adtran side. I am still working on Remote Call Control, not sure if it's possible, but if I figure it out I'll update this thread.
Here is the link.