"Science tells us nothing about God. It tells us a good deal about how the universe is. It tells us nothing about why."
Totally agree with that. I don't really understand why people expect science to provide any answers about God and then assume that this means there is no God when if fails to prove God's existence. I also think that just because there is no objective proof to date about God, it doesn't mean there isn't any. It is just one of many many things that we know nothing about yet.
"I'm always astonished at how so many people believe in god in the continued and universal absence of any evidence of his existence."
For plenty of people with a faith there is evidence. As far as they are concerned they have experience of God, a relationship even, and that this is all the evidence they need. Just because you don't accept their experience as evidence doesn't mean it is worthless. It is just your opinion.
"If you are right about god existing then he can grant any rights he wants. So of course they have the right to kill/mistreat non-believers/gays/etc. God told them so just like he tells you more reasonable things. Accept one and we must accept the other since we have no basis for distinguishing your belief from theirs"
You don't need a God for people to behave that way -I think you'll find Stalinist Russia and Maoist China both though they had the right to kill/ mistreat non-believers in their doctrines/ gays and other minoirty groups including those with a faith. This kind of behaviour isn't the preserve of the religious. They couldn't even blame a higher power for 'making' them do it!
For the record, I have read some of The God Delusion and all of the Selfish Gene - The Selfish Gene is better, probably because Dawkins stuck to his actual area of expertise rather than giving his opinion as fact. The God Delusion is like Dawkins in RL (well on the telly) a bit ranty, a bit grumpy and certainly joyless. I wouldn't make children read it - it isn't that well written and anyway, if you want to convert people to atheism and to see their error of the God fearing ways, you would do better to find a text trying to replace religion with atheism as something they must believe in. That would be counterproductive.