I too like to start new shooters with the 22, I am a certified NRA pistol instructor for what that is worth. I have heard better well known instructors bash the NRA instructors and from what I hear from them they really have every right. This does hit me hard as I feel I can give new shooters or people with little experience good basic handgun skills. With that said I also try to get through to them that if they like what I teach them and they enjoy shooting because I did my Job right they will need more training from someone that is a better instructor than me. What I am saying here is to know your limitations and don't try to teach what you don't really know first hand.
as Far a waivers go they really don't mean a thing, we had a riding stables years ago and had a lawyer draft our waiver, it covered every base, in the same breath he said it would mean nothing if we ever ended up in court, the waiver was to make them think because they signed it they couldn't take us to court.