Two things that your perpsective appears to be missing here:
1) Lots of people here were raised in religious families; they didn't start out privileging atheism. (Or they aren't atheists per se; I'm agnostic between atheism and deism; it's just the anthropomorphic interventionist deity I reject.)
2) You aren't the first believer to come here and present the case you are trying to make. See, for example, the rather epic conversation with Aspiringknitter here. You aren't even the first Mormon to make the case here. Calcsam has been quite explicit about it.
Note that both of those examples are people who've accumulated quite a bit of karma on LessWrong. People give them a fair hearing. They just don't agree that their arguments are compelling.
Thank you for pointing out perceived fundamental flaws. It's so much more helpful than disputing technical details.
1) I know that. However, I would guess that most people here have fully privileged atheism since the time they started considering themselves rationalists, and this is a big difference.
2) I was aware of that too; however, thanks for the specific links. I certainly got on here loudly proclaiming that I was religious; however, my original stated purpose was not to start an argument. That said, I really was asking for it, and when people argued,...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.