The only critters I've heard of who have an issue are cats, who can't *ingest* PG, it causes a type of feline anemia. I doubt if the vapor in the air would be a problem, as long as there is reasonable ventilation -- but I don't blow vapor *at* my cat, to be on the safe side -- if it lingers in the air, she likes to "pounce" on it, which is quite entertaining to watch.

I do know she finds my right hand far more lickable than when I was a smoker -- she wouldn't let my right hand get NEAR her, when it stank of stale cigarettes all the time. I've heard nothing regarding its effect on rodents, which probably means it's safe; the animals in that test from the 40's were monkeys, I think, and it was harmless to them.
As for people... there are allergies, and there are chronic whiners; sometimes it can be hard to figure out if a person has a real allergy, or just likes to hear himself complain, so he can control other people or just make them as miserable as their own tiny mind. Kids can be difficult, because they have very sensitive noses, but it might just be a matter of finding a smell the child doesn't object to -- and of educating the child that the world does not in fact revolve around him, and that vaping, unlike smoking, won't kill you or injure the child.
I was at my folks' house today; both former smokers, but neither has smoked in over 10 yrs -- and my mom has COPD. I sat at their kitchen table with them while they ate breakfast, and I vaped away quite happily, while they ate, also quite happily. I even asked them if they'd rather I left the table, and they both said "no, sit right there; it doesn't smell like much of anything" -- and I know for a fact that my mom would never let anyone sit at her table and SMOKE while she ate, even when she was a smoker.
Andria