All good points so I won't repeat them. Only thing to add is to mention where to vacate in an emergency, e.g. "vacate to the rear off the wing, away from the prop and I'll meet you 100 yards/metres upwind of the aircraft. Please don't leave the scene unless myself, or someone in authority allows you to do so."
in JAR/UK land I was allowed a written cheat sheet for the pax/TO. brief. However I had it memorised as my instructor insisted on at least one or the other on each flight!
Good luck.
TTR
All spelling mistakes are iPhone induced.