I think the fundamental misunderstanding here is not about replacing fear and suppression as a motivation for religion, but whether a belief in the supernatural (and a service structure that caters to it) is necessary in the first place.

From my early childhood on, it's one of these things that made me doubt if I'm even part of the same species as most people. I remember a vivid discussion with the local priest about why I stopped coming to bible class (I had only been there once or twice because my parents thought I was missing out on something). The guy said the problem was not that I was rejecting his faith in particular, what made him think I was really sick and disturbed was the fact that I didn't see why anyone would have a religion at all.