We constantly assert our will to obtain what we want. There are no physical obstructions/laws which keep us from making choices to our satisfaction. If this is all it takes to be free, then we have free will.
Nope, there are plenty of things in the world that behave in a probabilistic and non-deterministic manner. You can predict with reliability what populations of people or regions of the brain will do in certain scenarios, but not all cases, and not for individuals or neurons.