Do you know if the Charles City County records to which you refer include a will for James Fear? I am aware of a will for Joab Mountcastle (written in 1770) that names Elizabeth Fear as his daughter, although I have never seen the document itself. It is referenced in other documents I have seen.
I also saw a reference to Mrs. Elizabeth Fears in the Virginia Genealogical Society Quarterly, Vol. 25:
"Accounts From the Store of Thomas Partridge & Co., Hanover Co., Virginia (1756) p. 159 (excerpt)
Transcribed by Richard Slatten and James Bagby
Mrs. Elizabeth Fears. Mar. 13 (pd. her pt. for Separating a Hhd. Tobo. for R. EASTES, 2 Howes, pd. ROB. EASTES for her Levie 5/11); Dec. 17 (1 Felt 6/). Credits: Mar. 13 (by ROBT. EASTES). [Account settled and not carried forward.]"
Unfortunately, there is nothing to link this Elizabeth Fears to any other relations, although the entry suggests that she is widowed as of 1756 which would be consistent with a 1741 death of James Fears.
Regarding a potential father for my William, I like the Rev. James Fears, Baptist minister. He ministered in Grainger, TN and Pulaski, KY and is about the right age, both to be the father of William and the son of James Fears of Prince Edward Co., VA. Ira Fears suggested another of James' sons: Thomas Fears, the Revolutionary War veteran. Do you have any thoughts on this?