I have directed Best x-mas... twice at church with all different aged people in the cast. I love this story! I've not done it at my high school because I teach at a public school with a very diverse population . If you teach at a private Christian school, go for it! Might be fun to have teachers play the adults and the students play the kids. That show impacted the community in so many ways and kicked started my career in theatre education. I think the characters are fun and honest - as a Christian mom who has lived through many Christmas pageants I have known the adult characters in real life.
Break a leg!