I'd feel comfortable with a short "time out" taken in each classroom, each day, designated to allow students and teachers to pray (if they care to) in their own manner.
I'd have no problem with this if it was for "Thinking about the day ahead, our relationships with our fellow humans and, the state of our world". I'd let the parents decide if they wanted to encourage their children to pray during that time.
I would feel very comfortable with a short prayer said each morning in each classroom, in a serious manner, lead by the teacher or the students taking turns.
As soon as you involve a government employee to decide what the prayer will be about and how it will be conducted, you open it up to conflict. Most people have rather definite ideas about prayer and a lot of them have strong opinions. You also have the problem of those not wishing to participate feeling shunned or made to feel different.
I would feel most comfortable if this prayer was in the tradition of our historical Western culture, as it used to be, pre 1960's.
You still have all the problems above but they're made even worse with the even narrower basis.
We can teach children good behavior and how to get along with others without scaring them with the devil and hell or an all powerful God that will be displeased if they live somewhat differently than some religious or government figure says is correct. Let religion be taught in churches or other religious venues.
There are many common ideas that run through most religions that can be taught in a secular manor. Like do unto others and a lot of what Jesus taught. Old testament not so much but even it and the Koran have some.
