No. You misunderstood Dawkins on this point. He was referring to a higher power, to the universe. Of course we humans have objective right & wrong. Witness the Golden Rule. Every religion has some version of it. Why? It's the basis for morality: Do unto others as you would have them do to you.

The rest of your article is intriguing, but needs fleshing out. What kind of school shooting took place in 1856? Is it what we would understand as a school shooting? And are there stats to demonstrate a causation between forcing Christianity down every students' throat & a reduction in school shootings?