All that makes good tactical sense except the part of burning down Gettysburg. It was not the "Southern way"; it was not Confederate military policy; Robert E. Lee would never have done it. And it would not have been necessary to demorailze yankees.
Longstreet begged Lee to retreat after the first day. In hindsight, it would obviously have been better. Lee could not have won at Gettysburg, but he could have taken the draw on the first day and done what he done best----fight a defensive battle in the aftermath. Like your suggestion.
I am no military expert, but I know it made no sense for Lee to take his smaller army so far from his supply base and attack the much larger army after they settled into a good defensive position. But, if I had his job I would have destroyed the ANV in June of 1862.