this is certainly a tricky subject.. I usually don't vape in stores or buildings that i'll only be in a few minutes (i.e. walmart, lowes, department stores.), but i don't fell guilty about it if i do take a puff or two. If i'm walking through the mall or somewhere i will be for a while, i'll vape and not wory about it. That being said i don't blow huge clouds and try to stand away from people to an extent, but that's just being polite. I've never had anyone complain or say anything negative about me vaping around them, but if i was respectfully asked to stop vaping in a store or whatever, i would. I see it about the same as wearing overly revealing clothes or shirts with profanity on it. Would a person be hurting anyone if they did? no. are they allowed to? yes. is it polite or appropriate? not really..
I personally try to just be polite and ere on the side of caution. I ALWAYS vape in bars and at work, usually in restaurants, usually not in stores.
Also, one thing i thought i'd add... My dad doesn't smoke and has never smoked, HATES smoking, but has zero problem with vaping. Since i've switched and he's done some research (because he at least tries to stay informed), he actually goes around advocating vaping. That in itself has to say something good about exposing people to vaping. even the non-smokers.