I voted for number 3. Nothing should be considered pre-ordained or inevitable when humans are involved. Did the Conferedacy have much of a chance, no. But all they needed to do was to outlast the Northern will to suppress secession. It is possible in war to overcome superiority in manpower and materials, but that is going to require superior political and military strategic skills, which the Union possessed, not the CSA. The CSA never had general officers at the theater command level with the skills of Grant, Sherman and Farragut. Jackson was a great corps commander but at best the equal of Sheridan. Lee is sadly over-rated, a noble warrior but wedded to the outdated Napoleonic strategies of Jomini and a prisoner of the prejudices of his place and class. Of course it took the Union time to shuck off the general chaff that plagued the AoP early in the war and to find its true military geniuses. POD's can be developed that would deprive the Union of its best leaders and that could promote a slower advance of the Union which could lead to CSA independence from Union war-weariness. But in a way the military leadership was only a side show. As long as the political leadership was in the hands of Lincoln and Davis the CSA was all but doomed (flip heads 50 times in a row). Removing Davis from the scene before he was elected provisional president might help, if the CSA could have found a reasonable replacement, maybe Hunter, he could hardly have been worse (any friend of Braxton Bragg was no friend of the CSA). Bottom line for me, the best case for CSA independence is the removal of A Lincoln from this mortal coil by natural (non-Confederate linked) means, leaving the Union in the hands of Hamlin and Seward. That is not to say they would be incompetent fools, but I believe they would lack the sagacity, patience and iron will of A Lincoln. Best timing for this POD is before A Lincoln leaves Springfield, giving Hamlin and Seward time to possibly botch the opening moves leading to Ft Sumter and/or the lead up to Manassas 1. This would still not be a good chance for the CSA, but it is more than they had OTL.
Thought number 2, maybe a better outcome for the CSA is that Lee accepts command of the Union arnies and ignores the Anaconda Plan in favor of a Napoleonic strategy of attack to force the single climatic battle ASAP. A TL for someone?
Cheers to all.