prologos,
In answer to your questions: no, the story is neither literal and was never intended to be. Inherited sin is more of an Augustine precept. I usually use the expression: "supernatural superstition". These writers were, after all, Late Iron Age Canaanite hill-dwellers. They were not present at the time of the stories you are referring to.
Now, two for you:
(1) List for me where in the Synoptic Gospels (Mark, Matthew, Luke) Jesus explicitly states the precepts of ransom, fall and inherited sin.
(2) List for me where in the Synoptic Gosples Jesus explicitly states that salvation is based on faith in his death and resurrection.
Doug