Your optimism is, uhm impressive.
With the level of animosity that the south showed toward the north and their belligerent method of forcible withdrawal from the union, there was only two ways that the crisis could be resolved. Either the south returned to the fold or one side conquered the other.
Any other scenario would guarantee perpetual conflict.
There you go with the assumption there HAD to be a conflict. I don’t buy that.
The final straw over which southern Democrats broke their party apart, ensuring Lincoln’s election, was the issue of southern and slave access to all the territories. this was based on the theory that slavery had to expand or die, believed by both sides.
Yet we’re supposed to believe that the CSA would simply have walked away from this issue had war not broken out and have accepted complete exclusion from all the territories.
It seems much more likely to me that had Lincoln supinely agreed to recognize independence of the initial seven-stae CSA, tacitly or de jure, additional demands would have been made: surrender of some territories, return of all fugitive sllaves, CSA supervision of such return, etc.
The goal would have been to force a fight, because the original CSA was not really viable. They needed to get some or all of the remaining slave states to join them. No choice.
The break came at Sumter, but had Lincoln abandoned Sumter, it would have happened somewhere else.
BTW, that same belief that slavery HAD to expend meant that CSA independence would not have meant peace. They would have believed they had to expand into the Caribbean and Latin America.
This was not going to happen for simple logistical reasons. Given the technology of the day, the only way to stage such invasions was by sea. The Union Navy and Royal Navy would simply not have allowed such an invasion.