Lincoln really meant his “with charity for all, with malice towards none” line from his second innaugural.
Not only would the post-war occupation been milder with Lincoln, the lack of an assasinated President would have robbed the Radicals of a martyr for which to punish the South into subservience.
I agree that Lincoln meant to end the “late unpleasantness” as quickly as possible. But if he had lived, would he have been allowed to? Lincoln becomes the great President only after he was assassinated (much like JFK, but his legacy seems to be diminishing). He was able to run the war effort in his role as Commander-in-Chief, but I seriously doubt that Congress would have let him run the peace effort.
‘Ifs’ are great fun in history. If Lincoln had lived, how would we perceive him today? Especially if he had been politically neutered by Congress in his last term.