I agree that free will and materialism are incompatible. I do think it's possible that you can, without contradictions, believe in some free will. But it is binary, whether that belief is there or not. Even if you believe in some free will, you are undecided on the question of materialism, which is okay. But you are certainly not a materialist.
I currently lean hard on the side of a lack of free will. There are too many stories of people on drugs and having brain injuries completely changing who they are that I think the idea of earning an afterlife is a wash. I also think that free will is just cognitive dissonance in that it gives us a license to judge people with inferior biology without feeling elitest about our own good biological fortunes. For example, serial killers have biology that is incompatible with civilization. We know they need to be treated differently. But it's easier to say they are bad people who chose to harm others than it is to say they were given a poor biological hand, and we are just judging their luck.
I consider myself a permanent agnostic; I don't know much about quantum physics other than that it's a total fucking mess. To me, the question of free will is not that important since I think humans are fundamentally incapable of understanding the true meaning of it.