I wish I had all the answers...but

Page, I honestly wasn't sure why it is called brisket. I looked it up and it says that it is the breast or lower chest of beef. I know that brisket when it is pickled is corned beef.
Why does the recipe say to re-wrap, I don't know. That's the way the recipe instructions came. Perhaps, since the juice was put in a differnt container, it's just for appearence sake.
The flavor is like a BBQ, but not real strong. Sometimes I will add more BBQ seasoning or liquid smoke for a stronger flavor . At other times I will vary the flavor by adding a cup of strong coffee. This makes wonderful sandwiches on hogie rolls and is great for a do-ahead recipe for a large group. I usually buy the brisket at Costco, it's good and quite inexpensive..
Yes, a chuck roast would be good too, but the brisket has a little better flavor and being a thinner, flatter piece of meat, slices up beautifully for sandwihes.

If anyone else can elaborate on this, please do. I have a lot to learn myself.