I've just been skimming the last few pages, so if I repeat anything, sorry. I wanted to weigh in.
I took Princess into one store "illegally" as a tiny, tiny pup, other than that she only goes to the places with obvious allowance...petco, petsmart, PSP, vet, parks.
Once DD & I were out & decided to rent a movie so I was going to wait in the car while she ran in. I decided to ask them if I could bring her in & keep her in my hoodie & they said yes. Even though it was pretty dead in there I was so embarrassed! I did not like people looking at me & I was afraid people would think I was on a high horse.
So I decided not to do it again. Some people are ok with that, but I'm pretty shy sometimes so that's probably why I wont do it again.
As for others bringing their dogs in I can completely understand why they'd want to & why a biz would not.
As a general rule of thumb if it's not a place geared solely at pets I assume she's not allowed. I think if you build a relationship, so to speak, with a biz & they allow it it should be considered a specific thing with that biz. If they let you, great and if not take your pup out. That's just me & how I'd deal with it.