In the case of creationism, you're only vapidly correct. There's a geologic record, stratigraphy, and a fossil record that have to be accounted for. Simply put, no variation on creationism can account for all of those things. I don't see how some obvious creation myth, no matter how powerful the backers, can be taught with a straight face, much less in public school.

As far as intelligent design, I'll agree to teaching that, as long as we follow up on the consequences. First, what criteria can I apply on my own to decide whether a biological feature (the vertebrate eye, for example) is irreducibly complex? Second, what does the existence of intelligent design have to say about theology and the various hagiographies? Does ID make monotheism or polytheism more likely for example? Can we determine characteristics of God or gods based on examples of Design?

There are plenty of observational sciences, astronomy and geology and economics among them. What you wrote is hackneyed and untrue.