You say that "My son would obviously be expected to do all the curriculum like everyone else, religion included". Did you specifically ask the Principal about this? Here in New York City 23% of the catholic school kids aren't catholic - they're opted out of the religious instruction part of the curriculum.
Here in New York City 23% of the catholic school kids aren't catholic - they're opted out of the religious instruction part of the curriculum. At this school they do the religious studies too, and go to Mass as well. I did ask the principal about it, because my father, as a foster child refugee of the Holocaust, was able to attend a religious school in England, and he studied independently while the others attended the religious class.