I think I understand. Your original post was to solicit debate from both sides of the issue of “Does God Exist” from an imperical point of view. I think this is an apples vs. oranges debate as the nature of any metaphysical world and any laws that apply differs from the nature of any physical world and the laws that apply. As we are bound to the physical world, all of our observations and measurements that have led to the “Laws of Existance” are restrained to this one, any attempt to theorize a metaphysical system would be totally baseless as there is no way to measure and observe reality in that point of view.
Unfortunately I find this argument flawed. For example, remove God from this quote and insert “Third planet revolving around a sun somewhere outside of the Milky Way”. All of your arguements (no scientific evidence, unobservable, etc…) would apply equally with the exception of the concept of “Supernatural” being non-scientific. Does this mean that such a planet does not exist? No. Does this mean that such a planet does exist? No. I would think this puts itself into one of those Dual-Existance catagories, like spinning quarks and boxed cats.
Historically the answer is not much clearer. A few thousand years ago any thought that the Earth revolves around the Sun were totally baseless and laughable. Now we know otherwise and their positions seem ridiculous. A few hundred years ago most diseases were caused by small mice or dwarves that lived inside of our bodys and disrupted various humors. A few hundred years from now the concept of “Speed of light” may be totally busted due to some form of mathematical understanding. A few thousand years from now, who knows what civilization will think of God, our current concepts could be totally wrong. Or perhaps our current concepts of “Scientific Reality” are totally wrong. I would give the odds at about the same for either ID or Quantum Physics to be laughable at that point (or both, or neither, the odds are the same for all).
You can’t disprove metaphysical theory in the physical realm because it does not exist here and vice-versa. Check out some Kant for the various distinctions.