Films are pretty mundane work really. That was some time ago.
Costner is definately a superstar and superstars surround themselves with with exellent actors. He makes long epic films and his acting abilities have gotten better over the years. He once said movies are loosly based on scrips that are loosly based on the book. The director has ultimate artistic license. He likes to direct.
Costner does both and seems to pull it off. He pulled off the Hatfield and McCoys for the History channel, which was/is perhaps his best achievment yet (not his best $ maker though-yet).
BTW. The term "actor" comes from the Greek word "hypocrite".