The question about the flag at Seven Pines- apparently the only regiment in Armistead's brigade that got a battle honor from General Longstreet was the 53rd Va Infantry- Armistead's Brigade was in Huger's Division at Seven Pines- see below:
Numbers 18.
June 2,
The commanding general congratulates the troops of Major General D. H. Hill and his own upon their handsome conduct in the various attacks upon the enemy's intrenched positions and camps in the battle of the Seven Pines, on the 31st ultimo, and the defense of the position on the 1st instant. After a severe struggle the enemy was driven from his stronghold and all his artillery and his entire camp captured.
It is a source of deep regret, however, that these gallant soldiers, after thus taking the entire position of the enemy, should have endangered our captured stronghold by so far forgetting themselves as to desert their ranks for plunder. This bad conduct is more the fault of the officers than the soldiers. If officers so obviously fail to do their duty nothing better may be expected of the men.
The Seven Pines will be inscribed on the regimental banners of each regiment of the two divisions, except those few regiments that disgracefully left the battle-field with their colors.
The Seven Pines will also be inscribed upon the standard of the fifty-third Regiment Virginia Volunteers of General Armistead's brigade, Major-General Huger's division.
By command of Major-General Longstreet:
G. MOXLEY SORREL,
Assistant Adjutant-General.

I have been having a problem finding out what the flag issue to Pickett's Division after Gettysburg looked like as well- I suspect, by the number of unidentified flags captured at Five Forks and Sayler's Creek, that the flags issued after Gettysburg were generic, without regimental designations. However, this has yet to be confirmed-perhaps one of the flag experts on this forum could shed some light on this subject?- Barrett