Is it safe to vape with a 1.5 year old in the room?
Depends on the room size and ventilation available. A tiny bedroom in the winter with windows shut might not be wise. A large room, with open window(s), less risky. Proximity to the child also plays a factor, I wouldnt advise vaping with them on your lap, but if they're across the room, less risky.
Is it safe to vape in a car on a 12 hour trip with a 1 year old in the rear car seat?
If a window is cracked for ventialtion, AND the child has a proven track history of being tolerable of exposure to the exact juice, then I'd call that safe. I include the exposure history, because 300 miles from home, on the side of the interstate, is not where you want a toddler having an allergic reaction.
Is there any studies that say 2nd hand vape is good or bad?
Multiple studies of varying credibility on the negative effects of secondhand vapor. Most indications show no serious adverse effects.
What do you do around toddlers and kids?
Infants-Toddlers: Move away from them, to a cracked window on the other side of the room, or step outside if someone else can attend them.
Kids-Teens: Still vape at a distance, but you also have to get into the psychological game, cause they will be curious. I had to have a grown up conversation with my neice of 12 about what Uncle Signmaker was doing, why he was doing it, and why it's not something she wants to get into.