I'd be amazed if an AA agnostic/atheist meeting used the Big Book, for anything at all.
My homegroup does readings from, Do Tell! Stories by Atheists and Agnostics in AA
Hi. To your second question —
I'm an atheist in AA who has worked the 12 steps and continues to work them in my daily life. I have a sponsor, a home group, a couple service positions, and a couple of sponsees. I also have 1046 days not only without a drink, but without a desire for a drink.
That last part is maybe the most amazing. I was a daily, first-thing-in-the-morning, around-the-clock-drinker for a good long while. I tried quitting many times on my my own between 2008 and 2013. I tried everything I could think of except really working the AA program BECAUSE I was an atheist. And every time I wasn't drinking, every single day I wasn't drinking during those previous attempts, I was thinking about... no, I was craving a drink. To have gone almost three years without having to fight the urge to drink as a result of the work I've done in AA? Flippin' crazy!
Anyway, when I'd failed enough and got desperate enough, I came to AA despite my atheism and sought help. I knew that people in AA had something that worked and I was desperate and hopeless enough to check it out and see if I could get it to work for me, even if I didn't believe a god. And it did, when I got a sponsor, a home group, a service position, and I started going though the book with that sponsor and taking suggestions. I even had many talks with my sponsor about how and why I didn't believe in a god and he was patient enough to walk me through finding some conception, even a secular one, of a higher power that would work for me. He helped me be open minded to inventive ways of fitting my beliefs (or lack of one) into the steps and going through with the actions called for in those steps. He even got me to pray. Here's the weird shit... I still pray. I don't believe anything is hearing me. I don't believe anything is going to magically happen as a result of my prayers. I do have evidence in my life that the action of saying those prayers makes me more mindful of opportunities in my life. If I pray to be more patient in the morning and happen to find myself in a traffic jam on the way to work, the fact that I took time in my morning to ask for patients makes me aware that this traffic jam is an opportunity to practice being patient and not get worked up. I stay more balanced and calm. No magic or supernatural nonsense there — just good practical psychology. So I'm an atheist that prays. Ain't that a hoot?
Will there be a bunch of "Christ is the only way!" people in AA? Yeah, at about the same ratio you find them in society at large. And they're just as obnoxiously vocal as they are in society at large. They are NOT carrying the AA message. Remember, AA is not affiliated with any sect, denomination, or religion. It talks about finding a personal higher power, and that can be secular, like the collective Group Of Drunks staying sober by working the 12 Steps. For me, it's a personal spirituality that I adopted from a series of fiction novels and that I admit is completely fictitious but works in my imagination. But I have no deity, no god.
There's a lot of people working the AA program without religion or a god and getting lasting, meaningful sobriety. One of the Agenda Items at AA's annual business meeting (the General Service Conference) that takes place in a few weeks is to publish a book of Agnostic and Atheist AA members personal experience. And there's already an unofficial (as in not published by AA itself) book of this type available. Here's a link... http://www.amazon.com/Do-Tell-Stories-Atheists-Agnostics/dp/0994016239