Herb,
You stated:
"I have seen graves of Confederate Vetrans with a cross in lieu of a regular grave marker given by the Daughters of Confederate Soldiers. Would this marker indicate that the soldier was placed on the Roll of Honor while they were on active duty?

I have only see two markers as I described above...and they we so rusty that it was impossible for me to read any of the engraving."

....Herb, many CSA soldier's graves contain the regular Christian Cross. I'm certainly not an expert on CSA graves, but I would assume that it is what you see. That is, that the vast majority of CSA soldiers were Christians. The cross used by the UDC, on medals and graves, I believe is similiar to the "Maltese" Cross, where all four aspects of the cross measure the same (like the German "Iron" Cross).
There is a book, "Valor In Gray, The Recipients of the Confederate Medal of Honor", by Gregg S. Clemmer, in which he lists the recipients of the Confederate "Roll of Honor" by regiment, by state and by battle. He also lists other medals as:

Southern Cross of Honor , UDC, 1898

New Market Cross of Honor, VMI, 1904

Davis Guard Medal, 41 men of the 1st Regiment, Texas Heavy Artillery for actions at Sabine Pass, Texas, 8 Sept. 1863. Made from a Mexican 8 Reales piece,(silver) 38mm in diameter, in the shape of a Maltese Cross, suspended beneath an Irish green ribbon. These were actually presented by the grateful ladies of Houston.

The Texas Gold Star, given to R.E. Lee, consisting of 9 gold stars to be presented to soldiers of Hood's Texas Brigade. Actually presented in early 1865 to nine men from Texas and Arkansas.

The Stonewall Jackson Medal, commissioned by the Marquis De Lafayette in 1864, of 5,000 medals sucessfully ran the blockade, but wound up spending the war in a warehouse in Savannah, when they were rediscovered in 1893, and sold for $1.00 each to raise money for disabled CSA veterans.

Immortal 600 Medal, 1900

Gen. Nathan Evans Medal, gold, actually awarded by the State of S.C. to Gen. Evans for action at Leesburg, Va. on 21 Oct. 1861

The President's Guard Medal (Silver), a "rotating" award given to different men of the 25 Battalion, Va. Volunteers, beginning in 1862.

.....hope this helps...............Neal