Wow, this is a great read! I relly enjoyed those old posts by Brian.
One of the things that really helped me understand shot calling was the very first time that I shot a handgun in a dark house. We always talk about seeing the sights at the exact moment the gun fires, but it is hard to do sometimes. However, when shooting in low light, the muzzle flash creates this "snapshot" of that exact moment. I know this isn't available to everyone, but I feel that it is very helpful in learning what that "snapshot" sight picture looks like.