For example, if the universe just went 1 hour back in time, why would anything go differently the second time around?
Unless you can prove something is truly random in the universe, and not affected by anything else, are we not just on autopilot? I get the feeling from the moment of the big bang, I was going to exist and inevitably write this comment billions of years later, and nothing could stop it. I mean, 1+1=2. It doesn't matter how many times you run the simulation again, you get the same answer.
If you "ran" the universe over again from the big bang, then the probability that you would exist is essentially zero. I don't know enough about neuroscience to speculate on whether quantum mechanics has any relevance to brain functions over the course of a lifetime but from a physics standpoint it isn't inconceivable.
On a more philosophical note: if there is some true randomness in how our brain works do you think that that actually gives us any more control over our lives? It doesn't really change anything in my view.
"True randomness" in the sense that randomness is part of our current understanding of physics is just something not being determined by the prior state of the physical universe. It is, therefore, indistinguishable from things being determined by something that is neither part of nor itself determined by any set of things within the physical universe, i.e., "true randonmness" is empirically indistinguishable from the action of causes which are not themselves determined by the physical state of the universe.
Or, IOW, free will (that is, the ability to act other than in a manner determined by the prior state of the universe) requires (but is not implied by) a physical universe in which "true randomness" exists.
So, true randomness in the physical universe doesn't imply free will, but it is necessary for free will to exist.
God does indeed play dice with the universe. Eternity would be too boring without it. Of course, it doesn't hurt that he is both the dice and the one rolling them...