I started RHETT BUTLER'S PEOPLE this morning, and it brought to mind a comment made by a reviewer of my book. She said she was at first appalled that someone had the nerve to put Macbeth into a novel. I think "chutzpah" was the word she used. She decided that I'd done all right with him, thank goodness.
The author's audacity thing interests me. Yes, it takes some nerve to say you'll become the storyteller for Rhett Butler or Jane Austen or Cleopatra. But it's a story, people. It's just my idea or some other person's, and it's just for funzies. No one says you have to see Rhett that way if he doesn't line up with the man you met in GONE WITH THE WIND. I remember being quite unhappy with Vivian Leigh being cast as Scarlett, because I'd formed my own mind picture. But I still liked the movie.
So unlike some folks, I approve of the attempt to "capture" a character, real or imagined, and add to his or her story. Unless it's truly character assassination, I'll let you fill in backstory, continue adventures, or even provide motivation. Just do it well.