There are certainly areas where the government has the right to step in to prevent harm, regardless of freedom of religion. Sacrificing children to Moloch in an oven, for example, would probably be a case for intervention.

And if parental educational influence on 7 year old children was that immutable, the words "rebellious teenager" would be meaningless. Parental behavior and example teach kids far more than any "book learning" the parents might stuff into their heads.

I'm no more anxious to see kids taught creation science than I am for them to be taught Marxism, but this stuff has to be handled in a free market. Note that although I am virulently opposed to Marxists teaching on a campus, I would NEVER support any government law or legal action to prevent it. The objective is to educate administrators so that they can make the right decisions. Protests, letters, and particularly refusing to send your kid to that school, are some legitimate methods of applying pressure.

Once you have the government deciding what is "good" information and what is "bad" information to be taught in schools, then you are safe only so far as the government is reasonable, and being run by reasonable and educated people. What happens if hard-line fundamentalists get control? On what principle do you then object to their making creationism mandatory?