Your argument is a pedant argument. You're arguing about the full and proper meaning of the word belief. You keep trying to associate all these elements into atheism which are incorrect. There is nothing else associated with atheism other than the rejection of the belief in God.
Yes, you could describe that as 'believing there is no God', but, again, atheism is not the action, it is the reaction. Belief in god was proposed first, and atheism rejects it.
It has nothing to do with the afterlife. You can be an atheist and believe in an afterlife, it just has to be one that has nothing to with a God.
Maybe we die on this earth and wake up on another earth, called Bumsex, and we live all over again always finding the name of our planet strangely funny even though we can't quite remember why.