All your questions are absolutely justified.

First of all, it's absolutely fine to be uncertain of the answer to the question if god exists and it looks like you can't really prove that he exists or that he doesn't with absolute certainty and that makes the question about god more difficult or ambiguous than it really needs to be.

I think you should not ask yourself if god exists, but if it is reasonable to believe that he does and things will quickly start falling into place.

First you need to understand that the god concept as it is presented in most religions is actually unfalsifiable. This means there is no real way to disprove it. But we have to realize that this is true for any supernatural claim, even the most ridiculous one.

Let's look at an example of such claim that is not god. If I tell you that green unicorns exists and there is an invisible green unicorn in every room around the world and that the flapping of their wings (yes, unicorns with wings) is what created the universe, keeps the Earth spinning and fuels the Sun. That sounds like quite the ridiculous claim, right, but could you actually disprove it? Can you somehow prove that there are not invisible flying unicorns all over the place? If they are claimed to be truly invisible and supernatural you have no way to disprove my claim.

Still, it's absolutely rational to reject it, because the burden to prove something about it is not on you, it's on me, because I'm the one asserting all kinds of imaginary animals. If I can't provide evidence for the unicorns I'm talking about, then you can reasonably and logically reject my claim as unsubstantiated. If I haven't demonstrated my claim to be true, it's rational for you to reject it and to not believe in it even if you cannot prove and therefore cannot be 100% certain that the unicorns do not in fact exists.

We have this thing called the null hypothesis which is basically the idea that we should not make assertions without demonstrating them. So if I can't demonstrate that there are green unicorns, you should reject my claim. If I somehow find evidence in the future, you can change your mind, but for now in the absence of evidence, it's rational and logical for you not to believe me.

This is how we dismiss all the crazy mythological stories about leprechauns, pixies, ferries, flying spaghetti monsters, magic, powerful wizards and so on. You can't disprove the existence of any of those, but you don't have to believe them or to say their existence is a 50/50 chance affair.

The same burden of proof applies to god. If there is no evidence that would show you that god exists, you don't have a reason to believe in it. The fact that there is no good evidence that a god exists is justification enough to not believe in it.

You can also check out my post sharing the simple reason I consider myself an atheist here where I talk about the exact same issue. I've made a lot of points in the comment section there too.