Short answers:
Most of your questions are answered in Shelby Foote’s “Civil War” Volumes 1 to 3, each about 800 pages long.
Lee’s next moves after a Gettysburg win are explored in Newt Gingrich’s “Grant Comes East”, a sequel to his alternate history “Gettysburg” where Lee wins.
My next reading adventure after I’m done with Daniel Flynn’s “A Conservative History of the American Left” is Foote’s “Civil War” volumes. I’ve found some good prices for the paperback version on Amazon.
After watching “The Civil War” in which Foote was prominently featured, I was flat out amazed
http://www.youtube.com/watch?v=-szx8DJinBk
If Foote writes as well as he comments and speaks, I can’t wait to read it.