When showing the white light, I'd put angels at the far end to welcome him home. The shadow of mourners is a good idea, as the focus is the young man who has passed. All good suggestions as far as a pathway for those carrying the casket to the grave, and maybe move the grave stone back and reduce the size, with an open hole in the front. Put some trees, bushes and maybe statuary around different areas of the quilt. Maybe show an honor guard to the side, with bugle and guns, honoring him for his service. I would also do a scroll and do some embroidery with details about the young man. Bless you for honoring him this way!