Killer Angels Day 1 Leaves Me With Questions

After reading the first part of Killer Angels, it became clear to me how important the role of the cavalry was to a major army. Why was J.E.B. Stuart allowed to "joy ride" around the countryside without being demoted, courtmartialed, etc? Was there some kind of personal connection between he and Lee? Or, perhaps, is it possible Lee wasn't the strong leader everyone credits him with being? Also, when the advanced party came back and had seen signs of the Union, why didn't the Confederates scramble to take that wonderful "high" ground at Cemetary Ridge immediately? If he didn't want a battle there, why didn't he circle around behind Gettysburg and head to Washington? If Stuart had been doing his job, Lee would have
known about the approaching Army of the Potomac and could have headed south around the Union units and might have positioned himself between Meade and Washington, D.C. This might have won the war for the South. I also am forced to wonder what would have happened if Reynolds had accepted the appointment as the main commander. It seems that Lee and Longstreet were both surprised when he turned it down. What would the difference have been? Would someone else have moved their troops fast enough to support Buford's cavalry and take command of that wonderful position on high ground?