Probably the best scource to find this for yourself and read about it in detail is Harry Phanz's book, "Gettysburg The Second Day." I'm just finishing it up myself for about the fourth time, (each reading sheds new light on the battle as it happened on the southern end of the field on July 2). Longstreet was sort-of known for being "hard to move," how-ever he followed Lee's orders and got the attack under way. The real protester amoung Confederate generals on July 2, (south end of the field) was Hood, he thought it better to circle around the right and take the enemy from behind, "as Jackson would have done."
The delay due to "march, and counter-march" was nothing Longstreet did to delay anything, (as stated earlier, it was to remain unseen). The curious thing on July 2 was, Lee ordered several mounted scouting parties to the area, (and beyond) in the morning. These parties consisted of trusted and compitent officers who failed to report any Union troops in the area...Strange, seeing as Buford's cavalry division had camped there and was active on the morning of the 2nd, at least two regiments of Union infantry were "probing" the area at the time, Sickles had troops guarding the Emmitsburg road keeping it clear for his last brigades and ammunition trains to use, yet these scouting parties reported no enemy activity in the area. Would Lee have changed his plan if these scouts had seen, (and heard) the Federal activity going on in the area? Yes, it was early...And yes the morning was some-what misty with possible light fog in the low lying areas, but to not see or hear the activities of nearly two divisions...This is where Stuart's cavalry would have played a vital role. I do hate, "what if's" but in this case...
Longstreet probably beleived these reports up to the time he sent his own scouts out as his divisions were forming for the attack and they ran head long into Sickles advanced line, barely escaping with their lives. It was probably Lt. Col. Alexander who first made reference to seeing the Cemetary Ridge Line and realizing that July 2 would not be the last day when he advanced his artillery along the Emmitsburg road. Alexander saw clearly what Sickles had missed, the strength of the Cemetary Ridge line. Although they had smashed the advanced Federal line, the entire Cemetary Ridge line was solid, and would hold.
Longstreet may have generally disagreed with the attack, (prefering to take a defensive line) he was a professional soldier and would execute Lee's orders to his best ability as always.