Dan:
Great post.
This is more commonly known as the "Invisible Pink Unicorn" argument.
"invisible pink unicorn" - Google Search
Theomorphic:
In short there are an infinite number of possibilities in reality. One cannot function considering every last possibility in the world. To function in reality, humans have to entertain the most likely probabilities, and discard all unlikely probabilities. Yes, it's possible that if I don't scream the word "Potato!" at the top of my lungs that I'll drop dead at the end of this post - but the odds of that are so preposterously low, it is not even worth considering. In fact, I *cannot function* if I don't discard unrealistic possibilities. The same holds true with God. Now, the common agnostic response involves Pascal's wager, but do you really want to go there, Theomorphic?