Those are All Possibilities.
There is Also the Possibility that since e-Cigarettes do Not Leave the Tell-Tale Stink on people like Regular Cigarettes do, that Children will be More Apt to use e-Cigarettes. Because they know it will be Harder to get Caught.
So basically e cigs would adhere to kids that don't wanna smell like smoke right? And why would they not wanna smell like smoke in the first place? Probably cuz they smoked analogs and can now legally purchase e cigs to not smell like smoke. So they are switching to a healthier alternative. With that likely assumption said I think that just kinda blew thru your whole argument.