I drink a whole pile of coffee, but I don't think I'm all that addicted to it. Very dependent however, but if I can't get it I don't notice it. A friend of mine though gets headaches if he misses a day with coffee, and can't pee until he drinks it. Where I come from as well, it's not unheard of to drink about 10 cups of tea every day.
I'd say the real worry with caffeine is the hypertension risk in vulnerable people.
I like the angle discussed here that nicotine is a useful medicine though... I see there's much research ongoing. I know that a relative with schizophrenia gets a lot of relief by smoking because it regulates dopamine and the But I didn't think it could be an advocacy platform. You've seen the ads where they say "cigarettes contain nicotine, an insecticide" (it's an excellent one by the way, you should see the way e liquid clears my plants of greenfly), whereas they never say "cigarettes contain nicotine, a natural medicine".
The FDA idea that what we're using , even if it's technically correct, is a new drug is silly - the active ingredient is a plant derived oil used since the oldest mesoamerican cultures. Freebase or
salt form, it's all ends up the same. I think it's a conflation of "drug - medicine" and "drug - body affecting substance". E-cigarettes are not indicated for anything, so why would they be medicines? Caffeine's subject to regulation on dosage in No-Doz, but where it's not on pharmacy shelves we can use it as we wish.
/rant