I certainly agree with you on the historical relevence of the Old Testament books after Genesis. I do not, however, believe in the literal Genesis creation.
Not sure how that rates the 'however'.
I dont believe in a literal Genesis creation either. I believe the account a myth that contains with in it primarily religious truths, but a few scientific gems as well.
Even if the author of Genesis knew exactly what happened in the creation of the universe, I cant imagine that he could communicate it well to the pastoral nation of his time, and so used alegory.
The important Truths about Creationism are that:
1) the Universe has a design and a purpose.
2) that Life has a design and a purpose, and
3) that mankind has a Designer and a purpose.
Beyond that, using Genesis for inspiration as it was in the formulation of the Big Bang theory and then letting science do its job seem to be the best way to approach the situation if one is genuinely looking for the Truth about the world around us.