You're badly misreading the article. It does not say, as you claim, that "idea of an objective reality is a'“magnificent illusion [spawned by evolution] to maximize evolutionary fitness by driving truth to extinction.'" Rather, the article says that "The world presented to us by our perceptions is nothing like reality." In other words, the article presupposes the existence of an objective reality, which explains how we can coherently call our perceptions an "illusion." If there is no objective reality, then our perceptions can't be illusory, because the important aspect of an illusion is that it falsely represents something, namely, in this case it falsely represents objective reality.

Once you get to your long paragraph about God I lose track of what you are trying to say. Your specific question, "If we were unable to sense the cessation of God using any of the faculties to which we are availed--if the course of life would not be disrupted or impacted in any tangible respect--then God could equally exist or not exist, in which case his existence would be subjective and case-based," is not even a question, as far as I can tell, and I can't really understand what point it is making or what it is asking. You may find [this article]9http://plato.stanford.edu/entries/idealism/) helpful though.