We're not free to do what we want. We're constricted in every way. We can't fly unaided. We can't expand to 30 times our size. And in civilized societies we can't decide to kill someone and then go do it. We're not "free" to plot murder, so long as we understand we'll get punished for it. We simply can't do it. The only reason some people manage to do it anyway is because our crime prevention isn't good enough to detect the act in progress and stop it. God could, but he doesn't. When our technology allows us to stop people BEFORE they commit crimes, we will. (Oops, anyone thinking "minority report"?)
Your argument is faulty in its terms. "Free will" assumes that the "will" exists inside reality. Of course we can't "will" ourselves to fly unaided or grow 30 times our size. That's not reality. Otherwise there wouldn't be such a term as "free will" because it would be redundant if compared against fantasy. Unless we could accomplish anything and everything, we couldn't attain "free will."
According to the American Heritage Dictionary:
Clearly, we are not able to choose that which is impossible.
Your last point is a classic all-or-nothing bit. No, stopping a rapist doesn't in any way require me to also inhibit a person's thoughts. "Boy, I'd like to have sex with her" and actually planning to rape a woman are two very different things. (Regardless of what the Bible may say about it.) God could allow anyone to think anything, and only intervene when their actions impinged on another person's rights. Where do you draw the line? I don't, but then, I'm not God. Presumably, he would know where to draw the line.
Again, the debate was set within the realm of the bible by the originator of this topic. Whether you care about what the bible says is irrelevant to my argument. A person's thoughts are subject to sin according to the bible. In order to submit to perfect justice, it IS an all or nothing. Otherwise, God would be accused of showing partiality in His justice, which would be less than perfect.