You are absolutely right when you say that nicotine is highly addictive, but that's a function of the mode of delivery. When you deliver nicotine through the patch or the gum, so transdermally or orally, it's not very addictive at all. In fact, it has a very low abuse liability, and, as Dr. Khara said, most people don't want to use it. We have to encourage smokers to keep using it for the minimum amount of time.
E-cigarettes and vapour will likely fall somewhere in between. It's unlikely to be as addictive as smoke because it's all about the rate of delivery, the rate at which it gets into your bloodstream. Vaporized nicotine will fall somewhere between smoke and mouth or skin.
On the issue of concentration, you may know that the European Union has set a maximum concentration for nicotine in e-cigarettes. I would urge this committee to look at what's happened in the European Union and the U.K. because it's not as if a country has not tried to elaborate this regulatory framework.
Having said that, it's the user who controls the dose. You can have half the concentration and take twice the puffs or the inhalation. You want to make sure that it's not overly toxic per dose, but ultimately it might be a bit of a fool's errand.
On your last point about flavouring, real harm reduction advocates suggest that you keep the flavours in because that makes smokers want to use it. I think it would be more conservative and probably prudent to eliminate the cotton candy flavours, the cherry flavours. My opinion is that if an adult smoker is genuinely using this to help him quit, they don't necessarily need cotton candy flavouring to promote this product.