You are most likely going to get a lot better quality from a professional breeder. A lot of the pet store snakes are questionable. They can tell you anything about ch cb.
Little pieces of shed isn't a good thing. A healthy shed comes off in one piece. That is the good sign that humidity is good, nutrition is good, snake is well.
The fact that they are "Housed together" are you saying in one cage. That would scare me off IMMEDIATELY. One snake in there with a problem that spreads and they all have a problem whether you see it or not.
I've never purchased from Brian. You might also check out Ralph Davis. I trust Ralph and have some of his stuff. He's a good guy.