Wow - you raise a lot of deep questions in your post. I am 100% certain I can’t answer any of them to either your satisfaction, or the satisfaction of anyone else reading my post. What I can do, is present reasons and explanations. They are not air tight. They are open to challenge. I am happy for them to be challenged. They are merely food for thought.
There is no evidence for Christianity over Judaism, Islam, Hinduism or Buddhism. That is, there are no facts or information that indicate we should. This should not surprise us.
Christianity is not about ‘being over’ any other religion. Christianity in fact teaches there is truth in other religions. Christianity teaches Judaism was given to the children of Israel by God. As such, Judaism can’t be wrong. There are many similarities between Christianity and Islam, Hinduism, Buddhism.
The big difference is belief in Jesus Christ, in that Christianity teaches he was the Incarnate God. The Incarnation is a belief, and one that is impossible to prove in terms of the available body of facts. To me, facts that would prove Jesus was the Incarnate could never in a physical sense exist. For that reason, I would run with your agnosticism in that you can’t prove anything about God. This said, many things that cannot be proven are true.
The Israelite religion - it wasn’t much different to any other of the time. In fact, it was influenced by other religions. Scholarship suggests the Israelite view of God was influenced by tribes and peoples around them. Should we consider this unusual? Scholarship tells us the Bible is testimony to that. In the minds of people Yahweh was a tribal deity, and that belief evolved. Is that not something belief should do?
Did the person of Christ, as portrayed in the NT, intend to demonstrate to Jews their perception of God was all wrong? The reason I say this is I see such a contrast between the image of God Christ portrayed, and the image of God portrayed in the OT?
Concerning the existence of God, I am not persuaded there is any physical evidence. But, I am also of the view it is not possible to produce any physical evidence for the existence of God, and the absence of physical evidence does not of itself render something untrue. Also, what is true can very readily be disproved.
What you believe is up to you. What you believe does not have to be superior in order to be true. When you believe something, you should believe because it enhances your life in some way. If your belief does enhance your life in some way, you do not need to prove it,.
If you think others should follow the same path in life as you, you would seek to convince them to do so. If you see no need for others to follow your path, and have no desire to persuade them to do so, you would not seek to convince them of anything. You would be happy to leave them to make their own decisions, irrespective of that they are.