As an agnostic, I would also that this comment applies to this statement of yours, as well:
The concept of a sin nature is clearly taught in Scripture. Again, there are heroes and villains (Jedi and Sith)in the Sackett series. There is good and evil (light and darkness) in Romeo and Juliet. I do not apply fictional stereotypes to Biblical principles. If you want to equate Darth Vader to Satan that’s your prerogative. To me, doing so fictionalizes truths that are too important.
Both outlooks, seeing it as complete fiction vs. thinking it is beyond compare (too sacred) can be problematic. The former may dismiss its value seeing it like fairy tales just because it's not rooted in fact and uses a lot of myth. There is definitely some uniqueness and good, and perhaps even special principles in the Bible. In fact, it's not all fiction! I don't believe this applies to
William since he acknowledges the Bible's usefulness. As a Christian, I read the Bible, cover-to-cover, in 2 or 3 different English versions (Niv, KJV, etc), and as a non-believer I still continue to study it though not as much.
When it comes to the other outlook of the Bible being sacred beyond compare, I think that is looking it at too highly which can lead someone to miss the ordinary features. It is literature at the end of the day in that it is written by humans who are prone to error, cultural bias, etc. The same applies to any other piece of literature. Whether or not God is behind any of that, is still debatable.