I presume that you are aware of the NC Will for David ROZAR:
the North Carolina Wills R. page 145 1760 ROZAR, DAVID, Ann (wife), John, David, Shadrack, Sarah and Mashack.
So we believe that Shadrack's FATHER was David ROZAR.
I am inclined to think that Shadrack was probably named for his COUSIN Shadrack ROPER (b ca 1719 - Charles City, VA; d Oct 1784 - Powhatan, VA).You are probably aware that other members of this ROPER family were settling in NC, including the Halifax area, about this same time.
And this ROPER family settled in large numbers in Edgefield, SC, about the time you indicate that Shadrack ROZAR died there.Unfortunately, I do NOT have any specific information on the ROZAR/ROZIER children you identify which would link them to your Shadrack.