Remember, your post has (at the time of this comment at least) a score of 4. Subjects that are "taboo" on LessWrong are taboo because people tend to discuss them badly. You asked some legitimate questions, and some people provided you with good responses.

If you're willing to consider changing your mind, the next step would be to read the sequences. A lot of what you mention is answered there, such as:

Absence of evidence is evidence of absence The Fallacy of Grey (specifically, when you mention that because we don't know the whole truth, we can't objectively evaluate evidence) 0 and 1 are not probabilities This one actually supports what you were saying, where you were entirely right that you can't assign a probability of 0 to the existence of God. But you still don't know if this probability is 0.9, 0.1, 0.01 or 0.0000001. See http://lesswrong.com/lw/ml/but_theres_still_a_chance_right/