On the first point I think there are several belief systems that may claim to be religions that do not put a stake on moral authority, I would see neo-paganism, wicca somewhat in this realm and more strongly UU and Humanitarism.
For the sake of the discussion at hand, I think we can usurp the lexical or democratic definition of marriage and posit that a religion need not claim moral authority. These has the consequence of immediately negating Dawkins argument in the literal sense but I think it furthers the view that he is stating. We weaken the wording of his orginal argument and replace "religion" with "institution claiming moral authority", then the classic and perhaps the only examples are the classical religions which some people may claim are the only religions (by discouting our new, implied definition). The move is not a semantic one, but a clarifying one. It becomes that institutions which make claims to moral authorities are the root of evil. So religion is no longer a source of evil if it claims no moral authority. It portrays the classic religions in the sense that Dawkins wanted, since they all claim moral authority, and it sweeps the "hedonistic" religions out of the argument. By hedonistic I mean those religions that claim no moral authority and so allows complete moral agency of its members, since those religions would be labeled hedonistic by Christianity, Islam, Judaism, and others. Indeed I believe people have those very views about UU and Humanism.
With this definition in hand, it is much harder to argue against the conclusions as well. You aren't bashing religion per se, so you don't have to continuously show that religions do this or that, you simply show that the claim to moral authority of an institution naturally leads to coercion or attempts at coercion by that institution. I think the conclusion follows more naturally from the weakened hypothesis:
Morally right people do not want morally wrong things to occur. Given the chance to stop some action that they believe to be morally wrong, a morally right person will act to stop those actions. A large enough institution has this power. An individual who claims moral authority believes to know right from wrong in all actions. An institution with moral authority will seek to control people's lives down to the minute level, since it has the belief that minute details are wrong or right and the power to affect those changes.
Is this the essence of Dawkin's argument though? Wars and conflict arise because of institutions (governmental or otherwise) that view the actions of another nation, group, or institution as morally reprehensible and seek to remedy the situation through violence, in an "ends justify the means and there are no other means" sort of manner. Or did he in fact want to point out that this was uniquely because of religious thinking? In that, perhaps only religions define moral rights and wrongs against a spiritual entity as opposed to against a manifest organism?