Thats true, in fact I have an (extremely outlandish with little to no supporting evidence) theory that matter might be infinitely divisible, and therefore perhaps there are civilizations on much smaller bits of matter. Anyways, math isnt something we humans "discovered". We invented it. Math isnt some cosmic force that enacts things on the world, math is just our way of rationalizing it, categorizing it, and understanding it. Same thing as science. I also wouldn't say that math has infinite knowledge, its quite finite im pretty sure. People continue to expand upon it all the time, im sure we are far from having a flawless understanding of math or science.
Thats true, organic things CAN come from intelligent thinking beings, but that doesn't mean it MUST come from them. I would say that there is as much of a chance as any other explanation if not more than that of god.
Oooo okay i really like talking about philosophy. So, no. nihilism and atheism are not the same thing. Atheism is just the belief that there is no higher power. (Technically I would be considered an agnostic I think, since I believe that theres no possible way to tell what happens after death, what brought us here, or if there is a god, HOWEVER I still believe that the most likely option is that there is no such thing, and what some evidence already points to.) Nihilism stems from the idea that life is inherently meaningless, and that theres no reason to keep going since its worthless anyways. Another philosophy, existentialism, states that we as humans are to make our own meaning in life. But i don't align myself with either of these. My favorite philosophy is that of absurdism. Absurdism goes off the idea that life is inherently meaningless, similar to nihilism. Except, absurdism is about understanding this about the world and choosing to live anyways. Choosing to experience what you can experience while you can in your short mortal life, recognizing and embracing the absolute absurdity of existence and enjoyin it all the while. Rolling our boulders, so to speak.