On the contrary, by your own argument, an agnostic atheist would be demonstrating faith. (i.e. A belief (or lack thereof), in something that is unknowable).
Quite.
Whoa there. You are confusing atheism and agnosticism.
An Atheist is specifically expressing his faith that there is no god.
Note the use of the word faith, because as you correctly point out, absence of evidence is not the same as evidence of absence.
In this respect the Atheist has...