This keeps popping up in ever cannabis forum ad nauseam. It keeps getting shot down over and over again but it persists. I'd like to add to the O.P.'s second point.

2. Prop 19 creates several new cannabis related crimes with extremely severe penalties. Donâ??t pass a joint to a 17 year old, you will be looking at a max of 7 years in state prison, seriously.
Prop 19 only employs the laws already in place and mirror the state's alcohol laws. What you're parroting is a load of bull hockey.