Are you just playing God's advocate?

I like the Supreme Chemist (I think it's called) argument against (the Christian) God existing and humans having free will. It goes something like this:

P1) God is omniscient
P2) God is omnipotent
P3) God created the universe, all of its laws, humans, their DNA, and every subatomic particle jiggle that ever was or ever will exist in this universe.
P4) God knew the outcome of of his creations before creating them (from P1)
P5) God could have changed any single particle jiggle in such a way as to change any outcome he could possibly want to create (from P2 & P3).
C1) God created everything exactly as he did, knowing beforehand the exact outcome, with the power to have created it differently if he so desired.
C2) God is ultimately responsible for everything in the universe, including our very actions (that he foreknew and could have created differently if he wanted to).

We only have freewill in that we can't predict our own actions. But, God can. We are his creation. Don't blame the chemistry experiment that explodes when you knew it was going to explode before you combined the chemicals.

(A presupposition in my argument is that we do not have souls that exist outside of God's foreknowledge. If we do, then P1 is incorrect -- God is not omniscent. If he does foreknow the composition of our souls, and he created them, then those souls would still be able to be changed in accordance with God's omniscient omnipotent desires prior to creating them.)