I am not familiar with the libraries at Tech. I do know that there is an Alderman Library at the University of Virginia. It was named after Edwin Anderson Alderman, a son of James, both born in North Carolina. While they might conceivably be related to our Aldermans, I know nothing more about this family.
I also have no knowledge of a Dr Mason Alderman of Douthard's Creek. There was a Doctor Wallace Alderman of Douthard's Creek, born there, 28 May 1882, a son of Octavius M and Nancy A (Rider) Alderman. This may be the individual you're thinking of and he would have been a first-cousin of Sam Alderman. Note that "Doc" Alderman was not a doctor; that was his given name.
Thanks for Clarence's observation on Phoebe. It's interesting that Sam "kidnapped" your father, for a while. I have been unable to locate Sam in the 1930 census and perhaps that might explain his apparent absence.
As for who you're related to, you are probably related to every Alderman in Pocahontas and Greenbrier counties, so far as I know. Unless I'm completely misreading this family, your line came to what is now Bath Co, Virginia, in the late 1700s from Connecticut.