My problem with your argument against free will is that it in no way argues against free will. Instead it only argues in favor of predetermination. I agree that people's decisions would be the same no matter what, if no alteration was made to the world, it would turn out the same way that it has, the same would go for the future too. But the thing is, this in no way disproves free will. People still make all their own choices, have their own thoughts, and all have their own will. The only thing that this argues in terms of people's choices is that they aren't random or arbitrary, instead, people make choices, and if you were to replay the scenario, they would still do that. The main point of your argument is that the future will always turn out the same, but this would only really mean anything substantial if you already knew how the future would turn out, which you don't, thus meaning that all you've really said is that people make choices, and those choices lead to the outcome, which is pretty fucking obvious. And you might argue that, no, because the aforementioned choices are always the same, and thus the outcome is always the same, however, this would only really matter if you were to be going through life a second time, which you aren't, these predetermined choices are being made right now, people decide the choices themselves, and the outcome is based on the choices that they are making right now, it isn't as if someone else is deciding everything for us, we make the choices. And the outcomes haven't happened yet, they don't even exist yet, there are choices yet to be made that will affect them. Okay, all I'm saying is, your argument only matters if you're a time traveler, in which case you would then fuck with the so called predetermined timeline. It seems to me you make this argument to support a future that you believe will happen, thus the argument mainly being in favor of predetermination, but of course, the future you have in mind doesn't really hold much ground, because of course, it being just another aspect of your mind, of your own will so to say, one that affects the actions you take and things you say. All in all, the moment I heard your argument, I thought it was the stupidest shit I'd ever heard you say, and I consider you a pretty smart person. And so I've been thinking about it a lot and ended up here, rambling on about it. Anyways I'm not sure this will convince you, but I hope it influences your thinking, at least a little.