Well they do have magic powers if they can pray for you after they are dead. The story of the rich man shows that the dead can do nothing for the living.
Doesn't the story really say that the dead could do something but man being stubborn that if Christ's death doesn't do it, a sign from the dead won't do it.
Also, doesn't the story illustrate that the dead still have concern for their living brethern?
Yes, I believe it does. Think of the torment of being in hell to remember your past life and the ones you love knowing they are heading for the same place you are and not being able to do one thing about it. This story is a picture of hell, and IMO this is one of the saddest, scariest parts about it. I never thought about how bad it would be to have to think about my past bad life and that of loved ones for eternity. Sounds like hell to me.
Becky