Joyce, I think you're correct that Robert Bolling did not apply the strictest standards of genealogical research to his 1764 Memoir.His purpose seems to have been to write down what he knew from his father and other relatives about the history of the Bolling family and to say some things about his own background, education and accomplishments, employing language that, to say the least, reflects a strong sense of self-worth.As for pomposity in later life, well, he didn't have much longer to live.He died at the age of 36 in July 1775 while representing Buckingham County at the Third Virginia Convention in Richmond.
Scholar and author J.A. Leo Lemay has "rediscovered" Robert Bolling in recent years, writing extensively about Bolling's superb poetry and his role in helping to establish freedom of the press in colonial Virginia by means of a controversy he stirred up in 1764 about the improper bailment of a Virginia aristocrat named Chiswell.Although Bolling himself was from one of the "first families of Virginia," he had a strong sense of justice that put him at great personal risk and caused his exclusion from the legislature for ten years.His vulnerability seems to have been a weak heart, not his character.
I agree with you completely that "proof" of things shrouded in history is hard to come by.I think the basics of Robert Bolling's Memoir have stood the test of time, but he did not get into the kind of detail addressed here, namely whether or not Jane Rolfe Bolling had siblings."What hope for us" getting to the bottom of these matters 400 years after the birth of Pocahontas?I don't know.As long as people are willing to research the subject matter I don't think it's possible to know unless/until there's some kind of breakthrough.And even then I think it will be a matter of "the preponderance of the evidence" rather than proof, leaving people free to debate for the next 400 years (at least) about what constitutes the "preponderance."