In the matter of PUBLIC school, you're damn straight the government should trump a parent's authority!
Creationism has no place in any science class in any school with an ounce of self-respect. Otherwise why settle on Christian beliefs when $cientology is so much more profitable? Chemistry, biology and physics should all have a heavy dose of Thetans and a clearing or two.
I went to a Roman Catholic high school. Science class was "Science" - no creationism, no "God." The only place religion factored as curriculum was in Theology class - and each year the focus was quite different. One year was devoted to World Religions and covered Taoism, Buddhism, Hinduism, Christianity (a number of derivatives), Judaism and a few others including Islam. It was interesting. That class was mandatory each year. I can see offering some type of World Religions class in a public school as an elective the same way I can see a Political Science class.
Next thing you know you'll start hear about people trying to get Moses, Abraham and Noah into the history classes.
Bruno