So what stories are to be taken literally and which are not? And what is the criterion for judging?
Non-violence is the theme. That is the place to start, but I have been thinking about your question and want to give a little bit longer answer, because I know you are a thinker. You are good at raising difficult questions. Its a talent.
You and I are the result I think of an imbalance. We grew up in a culture that was out of balance and are a reaction to that imbalance, sort of like what happens in chemistry with a buffer solution or in other natural processes. Sometimes I criticize your approach to Bible criticism, not because I think you have no complaint but because I think you tend to cut the worm in half. That just creates two worms. You fight for truth, and while truth cuts it does not effect change when it enters the ear. It has to enter the will. What I think happens when you embrace the literalist approach to the Bible attempting to draw contradictions is you chop the worm. The fear of change and the fundamentalist assumptions remain, and you may even reinforce them.
What guidelines you asked me should we use to determine what is literal and what isn't in Bible stories. First of all, you and I are reading someone else's mail when we read the Bible. We are peeking into another person's house through a cracked door. Is it written to us and with us in mind -- no not at all. Its written to people following a peculiar way of life who have their own nadsat, and they have no responsibility to explain their business to us. Yes, its translated into English and sold on shelves, but its still not written to us, with us in mind. Its got no index, no explanations in itself, and it is unapologetically not for you and I. We are therefore put into the difficult position of being outsiders. Therefore there are no guidelines except not to make assumptions. Think of it as listening to one half of a phone conversation while standing in an elevator.