I would really like to see these arguments broaden from just Christianity to all religions. I feel that athiests (teen athiests, at least) target Christianity more than any of the other religions, which is fine, but I'd like to see athiest arguments against other religions as well for the sake of variety.
However, I feel that aside from it being ridiculous to believe, it should be abolished all together. It has done nothing except hold back science. Granted, our scientific knowledge and technologies are fairly new but if we were able to continue with scientific experiments at the time when the church was essentially the law, who knows how far we could be today. Perhaps we'd be at the same page as we are today but there's a greater chance that we would have discovered something else, something more and be more advanced.
Freedom of religion and separation of state and church came way before atheism became as popular as it is, in a majority of the world (and you could argue that the places that didn't have it would be making any scientific leaps anyways.) I'm still not well-versed on it, so if you have any good reads on religion holding back science, I'm interested.
I don't think it's religion's fault that people never questioned things.
The statement of science can answer how and not why is mostly true although I'm not sure why you posted it.
The only thing I can see that something such as christianity brings is happiness or hope or some other crap like that. You can get happiness from plenty of other places or things that don't require believing in something so full of nonsense. Or, if you do wish to believe in christianity for whatever reason, you ensure that you still can reason, be logical, etc... without having to give some stupid statement of "god did it". If you are able to do that and ensure that it doesn't somehow interfere in other ways, then believe if you must.
Religion and spirituality are big parts of philosophy. Some religious organizations help a lot of people out. Religion can help people overcome the fear of death. It can help some people find direction in life and become more morally righteous.
Religion has done as much good as it has done bad, but it could be argued that if we were all athiests, we would find different reasons to kill each other.