You're presupposing that the Darwinian evolution being taught is correct. One need not introduce God into the mix to discuss problems with Darwinian evolutionary theory -- problems that even big-name evolutionists acknowledge. If you're as serious about science as you make yourself out to be, I'd think you would welcome something like this, as it allows kids to see the scientific method at work.
Of course, we're still left with the question of God. "Science" tends to assume that God either does not exist, or is irrelevant if He does exist. As Stephen Jay Gould put it, "science covers the empirical realm: what the universe is made of ... and why it works this way and that the nature of religion extends over questions of ultimate meaning and moral value."
Gould couldn't imagine a scheme whereby science and religion could be unified -- a baseless assumption on his part that God is not active in space and time. If God does exist, then theories that incorporate His existence are certainly not improper; indeed, if God exists, your own oft-stated position on the matter is completely irrational. (Of course the atheist position is irrational anyway, for the obvious reason that it cannot prove its fundamental assumption.)
And, of course, God does exist.
Why is nonexistence of God a fundamental assumption? I'd say it's one of many assumptions a person can make (and not terribly important IMO).