Lagboltz: I haven't replied to your entire post, but two paragraphs impressed me as needing a response. This is not intended to minimize your other points. I just have a greater intellectual interest in the ones below.
I have been retired for over 10 years, and for the most part an atheist bible has already been written. There is no need these days for the Genesis to be so metaphorical. A science section would trace the universe from the big bang to stellar and planetary formation. Adam and Eve would be replaced by evolution, and the transcendence from Neolithic man to Paleolithic man.
Over the years, I've received criticism from some of my Christian and Jewish brothers and sisters for embracing the belief that theories like "big bang" and "evolution" are not necessarily inconsistent with a belief in God. I contend that since the Old and New Testaments were written to a great extent by human beings, the possibility of errors is very probable. I have no problem myself in accepting the possibility that God created the universe via "big bang" nor that He allowed development of many species via evolution. I have many many questions in the field of evolution that result from what I see as inconsistencies in logic and supporting data and rationale. Therefore, I don't accept Darwinism exactly as he stated the theory. However, I have an open mind on many of the details. I see no conceptual problem in accepting most science and a belief in God as being compatible.
Ethics are principles where man can live in harmony with each other, and his society can survive without self destruction. These principles are to some extent ingrained in the brain. Studies found that lower primates have a concept of fairness, empathy, etc. These principles can be printed in a "Bible" of moral codes, but moral codes such as the ten commandments are largely ignored by most anyway whether there is a fear of God or not. Unfortunately individual survival or gain often prevails over survival of the society.
The key concept in your above paragraph is the absolute need for a culturally-enforced set of behavioral rules! Moral-equivalency is NOT an option! Such rules of behavior can be enforced legally in some cases, and via cultural pressure/ostracization in others. I have serious issues with the societal norms presently deemed "acceptable" in the USA by most media, politicans, business executives, and individual citizens. If you were asked what ONE thing could be done to solve most of our nation's problems, the answer is simple, but not easily accomplished. If all citizens were ingrained in the homes, schools, theatres, etc. with behavioral rules that demand honesty, self-reliance, civility, etc., most of our nation's ills could be reduced enormously. Our government obviously believes that human nature can be modified, as many politicians have implemented anti-smoking campaigns, anti-obesity campaigns, cultural-sensitivity campaigns, etc. IF such cultural modifications really work, why not campaigns that enforce personal responsibility, self-reliance, honesty, civility, etc., and enforce those behaviors in our media, our courts, our politics, our businesses, etc?
"Good" societal norms used to be enforced on the basis of Christian principles. I argue that MOST of those religious principles were and are good ones worthy of obedience. In any case, the cultural decline in the US results to a great degree from a corrupt concept often called "moral-equivalency". If the left believes that gay marriage and abortions are morally "Good", then the left obviously believes that morality is a concept that can be stated in law and enforced! The left's claim, therefore, that the enforcement of a Christian view of "morality" is un-Constitutional is hypocrisy! The question here is "Whose concept of morality is worthy of societal enforcement"? I love debating that concept.
Thoughts?