The nature of time and free will is interesting, especially if you're considering a time travel game. Say you're from the future, and go you back in time to find Jack the Ripper. Now, you know what he's going to do, because you've seen it. Does that mean that it's not his fault he's killing people, that he has no free choice? That's certainly one way to look at it, I suppose, and it's definitely one way to prevent time paradoxes. No matter what you do, the past will always keep on going. Once it's happened the first time, it'll never change.
I'm a big advocate of free will. In one of my biggest games I ran, the PCs were opposing a Mind Flayer who basically wanted to control the minds of anyone he could. We actually got into some moral quandaries with prisoners who had been controlled by the Mind Flayer. In the aftermath of several fights, they felt pretty bad for killing people who might've been innocents. There was one NPC who had once been controlled by Mind Flayers, and who fiercely hated them. For her, it was a little extreme, to the point that she resented any authority. Through the course of the game, she, and the rest of the PCs, learned at least a little bit that many things are shades of grey, and that they shouldn't hate a whole type of thing just because of one bad experience. I think it helped that the aforementioned NPC was a dark Elf, who proved to not be as vicious as myths would have had the party believe.
So, God, do you suggest we use miniatures, counters, or tokens, or is it better to simplify the combat rules and use our imaginations instead?