1) Although my plan had three separate ways by which it could kill me, it was possible that all would fail, such that I would >wind up still in all the pain that was driving me to kill myself, plus on life support machines and with people hovering over >me annoying me

Been there... and have indeed talked about these problems with a friend who once said she was contemplating suicide. But i wouldn' t recommend this to all. I mean for most people the listening and trying to help them in their interest area can help better.