There were other Adair researchers looking at Adairs on the "James River", Bordens. Think the river was renamed and there was a ferry there, the Adair house was on the western bank which was later Pulaski co. (I think).Perhaps these Adairs may be connected to your William Adair and his dau. Sarah Keys ?They may have also been connected the the family with the surname of Christian.
The POAGE / KEYS / ADAIR / CHRISTIAN link may be -
Aug. 20 1766 Deed Book XIII, page 15. Joseph Ward and Janet to John Hays and Elizabeth Ray, 37,220acres conveyed to Joseph Ward by Andrew Brown, 21 May 1755, on Poague's Draft of JAMES RIVER, Borden's patent. Teste: Andrew WILSON Archibald ALEXANDER John Greenlee (csisv3,443)
Ward, Joseph (Jenet) to John Hay and Elizabeth Ray, 200 acres sold by Andrew Brown, 1753, 37 p, 1766, POAGE's Draft on Borden line. (hrcv,363)
Aug 2, 1766 Deed Book XIII, p.25. (Borden's executors) to Charles Hays, 6,200acres in 92100 on river side, Hays' Creek, ROBERT CHRISTIAN's corner on said creek. (csisv3 p.443) etc.
It would be very interesting to find the marriage records of the Adairs of this area.