Kiki, I think you have made some solid points, however, it seems most of you are confused as to what determinism has to say about free will.
No determinist has ever claimed we cannot act, choose, decide, etc, but that we cannot do this freely due to the laws of nature and antecedent events. So there is a will, it is just not free, or within our control. For example, say you put a Coke and a Pepsi on a table in front of me, and tell me to pick one, and I pick the Coke, there is no doubt that I have chosen to pick the Coke, the question is whether or not my will was free to decide that. Determinism says I was not, that because of my past experiences with advertisements for Coke, and maybe how my brain finds the color red to be more pleasing at a chemical level than Pepsi’s blue, then if I were to repeat that same situation a million times, I would never be able to choose Pepsi. This is a fairly simple example, but hopefully it makes sense.
If determinism is true, then there can still be morality, just no moral responsibility. The reason a determinist like Harris writes about morality is because we can still have influence on other people, even if we are not free. His work on morality can be read and be the antecedent event that determines you to think about morality differently.
I think that is what Sam is trying to convey. Determinism does not mean we don’t have a will or can’t make choices, but that the choices we make are based on antecedent events that compel us to choose one thing over another.