Chris, humans get to make their own choices as long as they don't harm others. The best thing you can do is help make it an informed choice whether to try it or not.... nicotine is addictive but so is caffeine. Luckily for us, the tobacco combustion part that does the most harm to us (and supposedly can affect others) is not part of the vaping experience. The choice here is one where a person, because of the addictive attributes of nicotine (if they go with some level of nic), can give up some control of their body, for some pleasure. That and what Jane mentions as to taking any foreign substance into the lungs is the cost of that choice. The payoff is the pleasure of the flavors and imo, more importantly, the visual of the vapor....
I've always believed and experienced this connection between the smoke/vapor and contemplation. I think that's why many of us here have come to the conclusion - it isn't a hard one for those that have tried everything else and failed - that half the 'addiction' is the smoke/vapor. And we're not alone: (I've posted this before):
"I like to think of fire held in a man's hand. Fire, a dangerous force, tamed at his fingertips. I often wonder about the hours when a man sits alone, watching the smoke of a cigarette, thinking. I wonder what great things have come from such hours. When a man thinks, there is a spot of fire alive in his mind--and it is proper that he should have the burning point of a cigarette as his one expression." Ayn Rand
Sherlock Holmes sat silent for a few minutes with his finger tips still pressed together, his legs stretched out in front of him and his gaze directed upwards to the ceiling. Then he took down from the rack the old and oily clay pipe, which was to him as a counselor, and, having it, he leaned back in his chair, with the thick blue cloud-wreaths spinning up from him, and a look of infinite languor in his face.
Holmes to Watson:
It is quite a three pipe problem, and I beg that you won't speak to me for fifty minutes.
Or, we can remember the case in which Holmes needed a pound of the strongest shag tobacco to resolve the problem and stayed alone all the day smoking, and Watson founded him in a sort of trance, in a room that "was so filled with the smoke that the light of the lamp upon the table was blurred by it, and my first impression as I opened the door was that a fire has broken out".
...... 
