The first thing is from UFO:Aftermath (which was a really good game, btw, lacking only interiors in a non-base missions and more destructable scenery). If I remember correctly, soldiers would stay in cover behind something and only peek out to shoot (like in the FPS games). It would be cool to also look this way around a corner to see.
The second is from Silent Storm, and is pretty obvious. The first shot require aiming the weapon, but the next ones only squeezing the trigger and correcting aim. Therefore, the next shots should be for less APs than the first one (if not moved or hit meantime).