Morality/Religion
I think these two overlap in many ways and secular education can offer studies for those children who with to select the options (or families who wish their children to take part) - the same as some people opt for art, or music, or school teams....
Now don't get huffy - religion and morality are of vital importance in our world which seems to be fracturing against traditional beliefs, while people prefer their children not be school in any one particular religion unless it is their own belief....
I would rather see the public education system attempt to expand enough to include as many variations on themes such as religion studies, independent morality and humanistic issues, even necessary legal issues which most people are going to be able to allow their children to partake in at least some of these.
As long as the basics of education (reading comprehension, writing skills, history, mathematical and scientific studies) to give a good basic in life survival, and let the students have some say in how they want to round out their first years in school as well as the extras such as teams or music/drama, etc.
If a school offered a menu of choices and mandated programs including extra course times.....then the students would have an opportunity to review at home with parental guidance.
I think religion can have a place in history and literature, but religious studies of particular faiths should be ex-parte from regular school work unless the school itself is a religiously based one - not of the general educational system.
It is important to discuss societal "right and wrong" issues, but these can be done without necessarily bringing specific religious belief into a generalized discussion.