You’re changing the terms of your argument on the fly. You originally said, “Whether God exists or not is a boolean question. With no evidence either way, its correct to assign a 50%/50% outcome.”
So, by your own logic, you cannot adjust the rate up or down without evidence, which keeps you stuck at agnosticism.
But then, in your latest response, you state that there is evidence for god’s existence after all but no evidence for his non-existence, a convenient position to hold if you tend toward theism.
I would ask, what evidence is there that fairies do not exist? If anything, it’s the fact that fairies have never been seen or reliably documented, which is the SAME evidence against the existence of god.
The Big Bang is not evidence for god any more than it is evidence for fairies. The Big Bang simply describes the first state of the universe that we can reasonably talk about, but doesn’t suggest anything beyond that. Also, the prime mover argument has so many flaws that it hardly counts as evidence for god’s existence, either. I wrote about the first cause argument here:
https://escapingplatoscave.com/2018/10/01/objections-to-the-first-cause-argument-for-the-existence-of-god/
If I wanted to prove the existence of fairies, I would need to do more than point out that you don’t have evidence that they don’t exist. Of course there is no evidence for the nonexistence of something that doesn’t exist. How could there be?
Likewise, if you want to prove that god exists, you have to do better than to point out that no one can prove his nonexistence. The burden of proof is entirely on you.
Let me end by asking you a question: what would change your mind? If you think this is a matter of probability, where Pascal’s Wager is relevant, then what piece(s) of evidence would ever get you to adjust the probability in favor of god’s nonexistence?
Unless you can answer that, then the answer is nothing, in which case you’re not really abiding by the apparent logic of the wager as much as using the wager as justification for a conclusion you favor.