Nobody asked you to do that. All you need to do is establish that life just arising spontaneously can actually happen. So far, nobody else has actually been able to demonstrate that.
If you can’t, then the probability range is 0 <= x <= 1, instead of 0 < x <= 1, which is a significant difference when evaluating a probability multiplied by a very large number.
Sure you did. The fact is that life came to exist on earth. Either it was Deus ex machina or somehow inert matter after absorbing energy of various sorts, was transformed into other molecules that came together as organic matter that organized into reproducible entities known as life. Now you can make an argument for deus ex machina if you don’t accept what some call the mystical fairy tale for physicists or the big bang theory. In the end 0x0 is always 0 so just what was at the core of the big bang and how did it get there? There is much mysticism at the center of physics.