IIRC, isn't the 'pariah state' trope derived from a statement Grant made in the last years of his life? Ultimately, the South's integration within the Atlantic economy (supplying ~80% of the UK's cotton import in 1860) by the mid-19th century is too substantial and extensive for it to be so rapidly-reduced to the status of 'pariah' in the first few decades following independence, no matter the consolidated moral and modern opinions regarding slavery. Indeed, the Southern crop of 1860-61 was record-breaking! Profit and production tends to triumph in the West at this stage in its civilizational development. Ditto for the North, particularly in regards to the textile mills of New England (whose lobby partly instigated the Red River Expedition for that very purpose, seizing and speculating cotton for their own ends). Trade and other factors also rendered Memphis and New Orleans wartime boom-towns. The Southern cotton trade will remain the most profitable and dominant for quite some time, especially in a scenario in which the industrial and agricultural interiors of Georgia, Alabama, and the Carolinas are not left utterly-bereft as in OTL 1864-65, permitting a more expedient economic and financial recovery in which foreign/domestic debts can be paid-off relatively quickly. IMO, African enslavement in the ATL will die a much more 'natural' rather than sudden and revolutionary death, with slavery being gradually abolished at the domestic state-level between c. 1880-1920, accelerating as the boll weevil infestation devastates many a field from west to east. The Upper South will naturally be the first to introduce such legislation, although South Carolina and Alabama will perhaps be among the 'hold-outs'.
As for Confederate industrialization and war production, this is one of the most poorly-understood fields of ACW scholarship. One cannot underestimate the effect of the Southern 'armaments miracle' that occurred under the tutelage of the Ordnance Chief, Col. Josiah Gorgas, who was a demigod in comparison to the bloated reputation of a certain Albert Speer. The War could've ended much sooner if, say Northrop, was in his position. If the entire South did not possess even a fraction of the production-potential of little Massachusetts for the entire 1861-65 period, then why was a single major battle not decided by a want for guns or ammunition, especially as the blockade became more effective, territory (particularly Tennessee) lost, and communications between the trans-Mississippi and eastern Confederacy severed in the aftermath of the fall of Vicksburg (and with it the Rio Grande arms traffic through Matamoros)? Why was the largest artillery barrage of the entire conflict conducted by a Confederate field army (despite the fuse issue)? Why could the Confederate Government provide Lee's disintegrating force with a train of more-than-enough ordnance, ammunition, caissons, etc. rather than provisions in the aftermath of the conquest of Richmond at Amelia Court House? Surely, even after Gorgas' efforts, the Confederacy was still handily out-produced by even a single Northeastern State (the Union's industrial expansion and organization was extraordinary in-itself). One 1861 estimation put the on-hand Southern matérial at only 159,000 small arms, 1,000 cannon of all (and obsolete) types, with most of these being seized at the Norfolk Navy Yard and other Federal coastal forts/arsenals by militia. Until 1863 only 10% of weapon production was domestic, with most of the arms utilized by Confederate armies being run through the blockade and/or scavenged from the battlefields. All the while, with Nashville and its powder facility lost, Gorgas was working tirelessly to develop the necessary cannon foundries, factories, and armories to reduce such dependencies, which proved inevitably difficult owing to a lack of pre-war skilled labor and machinery. Nevertheless, by 1864, Gorgas was permitted to state with confidence "Where three years ago we were not making a gun, a pistol, nor a sabre, no shot nor shell (except at Tredegar Works) -- a pound of powder --- we now make all these in quantities to meet the demands of our large armies." The need to establish a viable war-effort in the aftermath of Fort Donelson also caused President Davis to evolve what was arguably the most centralized national government in the Western Hemisphere until the New Deal, further destroying the various myths that have been propped-up. Let it also be noted that the alternative to the voluntary embargo in 1861 would have been a logistical nightmare for the nascent government, as Davis himself later explained.
Ultimately, the measures Davis enacted in 1864 to directly-control and regulate blockade-running import/export came too late, even though it did much to sustain foreign trade until the last weeks, and would have been of much benefit for the average Confederate infantryman if not for the laughable incompetence of Northrop. The principal Southern products (cotton, tobacco, sugar, naval stores, rice, and molasses) would be sent-out only under executive permit, whilst no luxuries (Parisian gowns, gold watches) not considered of absolute necessity for the common war-effort would be brought-in on vessels from Nassau, Bermuda, and Havana. This inevitably caused conflict between the seaboard and landlocked States, with the Congressional representatives of Georgia, the Carolinas, and Mississippi attempting to introduce a bill to nullify the new regulations, which was logically-vetoed by Davis. The duties were divided between two men, Thomas L. Bayne and Colin J. McRae, with the former supervising cotton-purchasing east of the Mississippi and the latter directing the sale of Southern staples and arms-purchasing in Western Europe. This was one of Davis' greatest accomplishments as a wartime leader, for by the end of 1864 he was able to report to Congress that his system had maintained trade volume with Europe, facilitated Richmond to distribute more supplies than formerly (if only Breckenridge had been made Secretary of War earlier!), and had transferred more profit into the Treasury than the private citizenry. Indeed, the siege of Petersburg was quite sustainable until the capture of both Atlanta/Wilmington and the desperation/deprivation induced by Sherman's marching columns. If the Confederate Government had successfully-attempted to seize control of its railroads, merchant vessels, and commerce due to earlier disasters in 1862-63, the South's strategic, economic, and financial position would have been much more robust, possibly-enabling ultimate victory. Alas, it was a matter of principle and the inherent greed and corruption entailing the stock-soaring business of blockade-running against the besieged walls of the South, with Davis, like a modern Macbeth, being the only one of note to remain defiant within that castle by April 1865.
We only have rough estimates for the ultimate statistical success of the blockade-running activities. Perhaps 600,000 small arms, 400,000 blankets, and large numbers of clothing may have been secured in 1861-65. Over the course of 1864 some 550,000 shoes were imported. In November-December 1864, 8.5 million pounds of cured meat, 500,000 pounds of coffee, and 1.5 million pounds of lead made it to port, despite anxieties and the deteriorating military situation.
In an independence scenario the Confederate States Navy will also have the means to complete, improve, and crew its significant ironclad contingent (the second-largest in 1864, IIRC), possibly permitting a practicable war with Spain over Cuba during the latter's revolution in 1868. You can also bet the Southern political elite will attempt to construct a great navy in order to avoid another depriving blockade and enemy river superiority, both key causes of defeat. Commerce raiders did achieve considerable success, but they were ultimately too few to seriously harm Northern shipping.
The main foundries were established in Georgia (at Macon, Columbus, and Augusta), with powder sites also being re-located to the latter. Selma, Alabama, was transformed into a new iron-manufacturing center until its own destruction during Wilson's Raid. Lead shot and artillery shells were produced in Salisbury, Virginia, and Montgomery, Alabama. Hell, according to Clement Eaton, at times the Southern divisions were better-armed than their counterparts, who, at least in 1861, were primarily-armed with the refuse of Europe, rendering frontal-assault slaughters such as Cold Harbor and Kennesaw Mountain feasible.
The early loss of Tennessee and its industrial potential is what makes these facts all the more remarkable. Although Tredegar Works in Richmond continued to produce the main quantity of cannon through the end, Tennessee contained a wealth of iron ore and other metals required for armament production. Consequently, new coal and iron fields were developed within the interior, birthing the expansion of Birmingham, Alabama's steel industry (a pre-war idea conceived by the aristocracy, IIRC), rendering a manufacturing base on the scale of Pittsburgh possible. Nonetheless copper, mercury, and lead still had to be obtained primarily through the decreasingly-effective blockade-runners.
The railroads are also a fascinating topic. During the War, for want of maintenance and other resources, the lines gradually-deteriorated, making inter-theater transport of divisions nigh-impossible after Chickamauga, mostly due to time, limiting the importance of interior lines. Thus the Confederacy suffered from worsening domestic transportation and distribution, even when industrial production was rendered sufficient in 1864. It would appear the Southern leadership would desire to improve its system in order to match the demonstrated superiority of the Union. All things considered, I'm certain foreign investors could be found for such projects with the promise of more expedient shipment of Southern staples to the seaports. Perhaps something resembling a transcontinental railroad could connect the South from Norfolk to El Paso.
Post-war Confederate politics is a topic deserving of its own thread. I have some ideas, with a bilateral party system (Nationalists and Libertarians) descended from factions divided over the Davis Administration and its performance/legislation. A Populist organization could also form in the lesser-developed States. If the wartime industry survives, that would contribute much in the way of immigration. But the Confederacy would never be reduced to the status of Central America-tier 'cotton' republic, military dictatorship, nor a communist state, despite the inevitable political, economic, and social difficulties that are certain to arise within a century of its establishment, despite probable post-war economic reconstruction/expansion. I think by ATL 1914 the CSA will be considered a great power, with more appreciable military and industrial potential than several European nations, but still inferior to its northern neighbor in those regards.