Is God not allowed to use allegory? Christ used parables to teach, would His Father not have the same right to put the story of His creation into terms mortal man could grasp?
As for this being an issue to cause doubt for the literalness of other passages of the Bible, personal prayer for guidance and study of each part you may question seem to me to be a good first step in asking God for aid in understanding His Word.
If Adam and Eve aren't real, then neither is sin. That simple. No way around it. So why is he death of God's Son necessary again?