I did not say that belief affects possible existences.
Can you name one god that isnt imaginary? Hint: you would need to produce evidence of (or a hypothesis for) gods to make them not imaginary.
Lacking a hypothesis.... edited for brevity/character limit
Lets simplify here, and if I skip anything you really wanted a response to, I'll be happy to answer next post if you point it out.
We can agree on the fact that we have no knowledge or evidence that shows gods to be either possible or impossible. The truth here is unknown, but there is a truth, and it is one or the other. I have two approaches here, one of which just being a play on the word "possible". There's a reason I framed the OP in terms of certainty as opposed to possible/impossible. Impossible implies 100% certainty, but "possible" is a rather squishy term.
First, gods
appear to be possible because they have not been proven to be impossible. Gods might be possible, they might not be possible, we don't know. The lack of knowledge gives the illusion of possibility. Like flipping a coin, catching it, slapping it down on the table and keeping your hand over it. Assuming this is a standard 2 sided coin, it's heads or tails. It seems possible it could be either, but in truth it is only one or the other. Tails seems possible, but if the coin is heads up under your hand, tails is not actually possible. This is the illusion of possibility that comes from lack of knowledge. But if, with your hand down, you ask someone "is it possible the coin landed tails?" they will universally answer yes, even if the coin has already landed on heads and tails is in fact impossible. The problem is that, in our ignorance, we can not tell the difference between what seems possible but is impossible and what is really possible. This is just the dual nature of the word "possible" in the english language. I'm going out of my way to acknowledge this because we'll go round in circles chasing our own tails if I don't. Even if I could contort this into a cheap win, I'm not interested. This is just a play on words like I said.
Second, and this is really the meaty part, is how we treat the unknown.
You throw that word "Imaginary" around like it means something here. Before, you've stated that imaginary things can be dismissed without evidence (although you refused to say they were impossible) much like a child's imaginary friend. I have to admit it's caused me to stumble because it's hard to counter. You don't really commit to anything with that position, so there's little to argue against. But this is really just a red herring. Human imagination, adult or child, has nothing to do with possibility of existence. Ask any successful inventor. You could certainly say that often the human imagination produces ideas that end up being impossible (inventors will agree there too). But you can not turn this into a blanket statement that all things imaginary do not exist or are impossible. One does not follow the other. And you beat me to the punch, knowledge does not affect possibility of existence either, more that we agree on.
I feel it boils down to this: Is the unknown possible, impossible, or neither (without using the play on words above)? I would say no to impossible right off the bat. To claim the unknown is impossible is to try and confine ones self to a mental bubble, where certainty is assumed. To claim the unknown is possible is to play the naive eternal optimist, and be disappointed after having every lottery ticket checked because you never watch the news and don't see it being announced there was no winners (And thus you believed it was possible you hit the jackpot right up until the machine checked your numbers). So we are left with neither. Taking care to acknowledge the things we can not be certain about, respecting peoples beliefs because we know that we can not disprove them with certainty, even if they take a tremendous leap of faith to truly believe in while retaining a rational mind. The point of this thread is that atheists that debate as though they were certain gods do not exist or that gods are impossible have no business doing so. They have made a similar leap of faith, if in the opposite direction and not quite as big as the theist. There is no certainty with regards to the unknown. My 99.99% certainty is hyperbolic, I'm a bit less certain than that. But, the truth being unknown, 99.99% certainty is the upper limit (without going into the 99.999%, 99.9999% ad infinitum). 100% is not possible, otherwise we would not be referring to the truth of the matter as unknown. For those who act certain, that last .01% is an assumption and nothing more. And that assumption means you are not 100% certain.