David --

If African-Americans were as common in Confederate service as we're led to believe, it's difficult to imagine why there would have been much of a stir in the ranks when the government proposed enlistment of African-Americans. Newspapers from that period carried comments from soldiers, memorials by specific regiments &c. It sure seems to be a new and controversial topic, even though Southern editorial writers printed suggestions for and against the idea as early as the summer of 1863.

To follow up on your notes about military laws, the Conscript Act doesn't restrict by race or color, but does apply to white men only. Other laws, such as this one, grant permission to enroll blacks only for specific purposes --

The Congress of the Confederate States of America do enact, That hereafter it shall be duty of the Captain or Commanding Officer of his company to enlist four Cooks for the use of his company, whose duty it shall be to cook for such company--taking charge of the supplies, utensils and other things furnished therefor, and safely keep the same, subject to such rules and regulations as may be prescribed by the War Department or the Colonel of the Regiment to which such company may be attached:

[SEC. 2.] Be it further enacted, That the Cooks so directed to be enlisted, may be white or black, free or slave persons; Provided, however, That no slave shall be so enlisted, without the written consent of his owner. And such Cooks shall be enlisted as such only, and put on the muster-roll and paid at the time and place the company may or shall be paid off, twenty dollars per month to the Chief or Head Cook, and fifteen dollars per month for each of the Assistant Cooks, together with the same allowance for clothing, or the same commutation therefor that may be allowed to the rank and file of the company.

APPROVED April 21, 1862.

Even in Confederate units (like the Richmond Howitzers) that are supposed to be full of African-Americans, I've never been able to find evidence of them aside from body servants, cooks and musicians.