Answer

1. Listening is not a material matter. Where did you get that from? Our listening is done through mechanisms that receive sound waves, which is a physical matter. But there is no reason to assume that the Holy One’s listening is physical. A message goes out from us and is received by Him. In what way? I have no idea. But He says that He hears. If you believe the Torah, then that is the given. If you do not believe, then indeed there is no point in the whole discussion.
2. It is not true that you are supposed to be certain that someone is listening. There is no certainty about anything on earth, not even that I am here and receiving your message. And nevertheless you sent it to me. It is enough to assume that He is there, even without certainty. That is how it is with all our claims about reality. There is no certainty in any claim, but that should not prevent us from forming positions and acting on them. The mistake of postmodernism is that it identifies uncertainty with doubt. Doubt is 50-50; uncertainty can be 90-10 or any other ratio. By the way, that is also how it works in Jewish law. Not every uncertain piece of knowledge is a state of doubt.
3. Maimonides’ negative theology is, in my opinion, a very problematic thesis, and personally I tend to think it is incorrect. In any case, I would not assume it as the basis for a difficulty.
4. Regarding individual providence, I have written a lot about this here on the site and in my trilogy. To the best of my judgment, there is no divine intervention in the world, but there is passive providence (monitoring our actions). In any case, our actions do interest Him. The nature of that monitoring is unknown to me, but there is no reason to assume that it is material; see section 1.
5. Therefore I see no impediment to praying to the Holy One, as long as you believe in His existence and that He is listening.
All the best,