For the "if Satanists = atheists, agnostics = theists" part of your FAQ, this probably wasn't the best choice since agnostics can be either atheistic or theistic in their beliefs (or lack of).

You are correct. However, I use agnostic in the colloquial (meaning one who does not believe it's possible to decide whether or not there is a deity) rather than the purely philosophical sense (which is more openly defined).