I think you would benefit from what is inarguably the best work on "James, the brother of Jesus" (title), written by the late Dr. Robert Eisenman. Another book you might find interesting is by Dr. Eisenman's protogé, Dr. James Tabor and his work entitled "The Jesus Dynasty" where Dr. Tabor eschews much of the RCC's manufactured history of Jesus and points out that the family was indeed prominent Jewish "royalty" so to speak, and was most likely part of, as you say, the Sanhedrin.

Like you, I also do not buy the virgin Mary myth either. Calling Mary a prostitute isn't helpful either. I think people stretch to find meaning in lRCC myths here.