The true underlying flaw of the South was not slavery, but it's attempt to recreate a society based on the gravest flaw of European economic and governmental systems...
ruling aristocracy and working serf/peasant status determined by birth.
The concept that birth determines one's position in society and not one's own efforts and inborn gifts is a European failure.
A society that does not allow people to rise or fall on the basis of their own inherent abilities is not a society that will advance quickly or face adversaries successfully in the long run.
I don't see a rosy future for a Southern Confederacy as you do. I see an inherently unAmerican concept leading to its eventual disintegration at the hands of some conqueror or another from outside, despite the exemplary valor, courage and patriotism of its soldiers.
I haven't thought through the latter part of this post as I haven't thought much about what the effect of having another European style aristocracy established in the Americas would work out, but absolutely do believe the first part. And if one looks at Spanish influenced countries (Mexico, South America), there might be a clue about the future of such social systems.
Forget about the Confederacy. The article focuses on the concerns and values that gave rise to the American Revolution.