But being addicted to e-cigs is OK because all it is is nicotine and nicotine never killed anybody
I just read The Poisoner's Handbook:
The probable lethal dose of nicotine has been reported as between 40 and 60 milligrams (the total amount in about 2 cigarettes if all of the nicotine was absorbed) in adults and about 1 mg/kg in children (less than 1 cigarette) . Children may become ill following ingestion of one cigarette, ingestion of more than this may cause a child to become severely ill. In some cases children have become poisoned by topical medicinal creams which contain nicotine.
YMMV