You and I probably end up at the same conclusion...that the Bible has little to no place in primary or secondary public education...but we take different routes. I disagree that there is not significant importance to be found in the Bible, but I also believe that of other religious texts such as the Qur'an. I think this is true because so much of civilization as we know it today has been shaped by these books in one way or another. However, I think that a reasonable discussion of these topics with comparisons and discourse is not possible in any elementary/primary settings and exceptionally unlikely in most secondary/high school settings. Therefore, I think such topics should be left to higher education at least for now. Honestly, too many people would be too dug in to having the texts taught as dogma rather than as historical documents for me to believe they have a place in public education right now.
Even fiction serves to shape civilization and we teach historical fiction for that very reason. The issue, to me, with religious texts is not that they are factual nor that they are fiction. The issue with them in most classrooms is the visceral and unavoidable disagreement as to which category they fall.