Your inability to do this will be conclusive proof that I am right here. In any event, any of those scenarios are nothing more than pure speculation. The fact that they are not immediately dismissable is why I am agnostic rather than atheist. If you state God does not exist you are an atheist. It is common to be atheistic about the God of the Bible, for example, while not automatically discounting any possible superior or supreme being.
Skepticism is intellectual doubt, while atheism is absolute disbelief.
These are hardly the same thing. If you say you do not know if God exists and it is impossible to prove it one way or the other, you are an agnostic. You're limiting your definitions to views about only one possible version of God. When one considers all possibilities, one's views can range all the way from strong belief to strong atheism about any given possibility. I'm quite certain that their are versions of God that you flat out disbelieve just as strongly as you believe in your own personal version.