Here's a key difference in our perspective, however: you're suggesting that only a small portion of this god would be used for the universe. I'm suggesting that it could be half of the god, or even the whole god. We can't theorize what a god would be made of. It could be that he has no "body" and is all "mind". In that case the god could have essentially turned himself into the universe.
Even if you take your example of a god turning itself into our universe that process would involve the transformation of energy from one form into another, assuming that this transformation follows the laws of physics then a certain portion of that transformation would involve entropy losses. Hence you still have the same problem that you had before just on a smaller scale.
If you want to say your god is utterly unfalsifiable that is fine by me, I thought that anyway.