Might as well throw in my two cents...
I have read both books and enjoyed them for the entertainment they are - they are alternative histories, pure fiction based on <i>possible</i> courses of events. To answer some of the questions:
1) Could Lee have moved south as depicted in book one ("Gettysburg")? Very doubtful. The ANV Supply train was still west of Gettysburg, as was Pickett's division, and neither would have been able to get to a road to cut south on the east side of the mountains in time for the ANV to move south as a unified body by the afternoon of Day 2 - as it was Pickett didn't arrive until late evening on July 2 and the wagons would have been behind them... so moving south on July 2 while Stuart demonstrated north and east of the Union line? The demonstration would likely have been possible as depicted, but getting the rest of the ANV south on July 2 would have taken a feat of logistical coordination that not even UPS or FedEx could have pulled off.
2) I had no problem with Meade attacking the Pipe Creek line - it is backed up in the book by pressure from Washington, and from my view of Meade, he was not the type to openly go against his superiors, even to the point of executing pointless orders out of spite (such as in the Overland Campaign of 64 while Grant was looking over his shoulder). That Meade would also sit around Gettysburg and continue to concentrate while Lee moved southwest I have no problem with because, as I have mentioned, he was not very agressive/offensively minded. I think if Longstreet and Meade had commanded armies against each other, the two sides very well would have sat on opposite sides of the same valley and starved to death before either attacked.
3) Why did Lee stay and fight? He said himself, the enemy was there and he must fight them there. The ANV at this point was stretched for supplies and only had ammo available for one large battle. He had little intelligence thanks to Stuart and strategically there were few options left other than to attack. He couldn't move northeast because then the Union army would be in his rear and have easy access to his already tenuously long line of supply and communication - lacking most of his cavalry corps, he couldn't leave it vulnerable. As I mentioned above, this is also why he couldn't easy move South/southwest on July 2 - no way to get the wagons and artillery reserve safely past the front of the Union army - an aggressive push west as Sickle's requested and attempted in the book could have destroyed the ANV easily if conducted on a large enough scale. Lee had gambled with such moved in the past (especially Chancellorsville, with a smaller army) but the road network on the Confederate side of the field was not condusive to rapid north-south movement. It was either go back across the mountains and move south (tantamount to admitting defeat) or try to force the Union off of Cemetery Hill and regain the initiative.
Notice I say push them off of Cemetery Hill, not the Round Tops. I've just read Troy Harman's "Lee's Real Plan at Gettysburg" and highly recommend it. It isn't fancy, and I wouldn't put it up with the likes of Gordon Rhea or Peter Cozzens for writing ability of the author, but he makes a very strong case that our perceived ideas about the Round Tops being the key to the battle are completely false, especially through the eyes of Lee at the time. Reading that book could drastically change your views on the battle of Gettysburg and give a new understanding of Lee's actions. It isn't long and is an easy read.
I suppose I should stop preaching now?
Regards,
Captain Alan Lynn
3rd Battery "Jacksonville Greys"
4th Div, II Corps, AoA
God bless <><