I don't see that there is any basic difference between Atheist and Theist societies, as they are all religious. What's more important is the style of belief or disbelief (and the values which go with the belief system).

Just by reading your contributions it is easy to see that some people are more Fundamentalist in style than others, and that being an Atheist does not protect you from being a hard core Fundamentalist or stop you from trying to convert others to your beliefs.

Obviously living society which matches your beliefs would be much more comfortable, but if you do live in a society with contrary beliefs then it would be much easier if it was low on fundamentalism.
Despite this, as TheFallibleFiend says, there are other things which are much more important than belief or disbelief in a deity. If you were an Atheist in an Atheist society, a conflict in values between you and your society could be much more significant than being an Atheist in a Theist society if your values generally matched those of your society. .e.g Communists living in Nazi Germany (I am not sure whether the Nazism was officially Atheist, but they come across that way, especially with their semi deification of the Arian race).