We run Medware on Win-7, but on a workgroup. Have for years. I have never found any good way to back it up reliably except to copy the entire EMedware folder to DVD or other hard drive. It has worked on the rare occasion we have needed it. There is no backup program that I have ever found, and they haven't even been able, or willing to tell us which files need to be backed up so we can create our own backup program.
I agree entirely with the progressive degradation of support -- although except for this one issue it has been pretty good. In the old days, it seems like the programmer staff was also the support staff. Those days are gone.
I'm guessing that you are right, and somehow it can be made to run on SBS without admin privleges. Probably whoever we talked to just didn't know anything, and gave the usual safe answer: "you can't...." We didn't push it. For the real install, I might call Medware support and tell them to please make it work; for now, it is enough to know that it does run under SBS.