It's either or for us. It's either, he's coming in with us, until the shop owners says otherwise or Kairoe is tied to a pole and within sight. You would be amazed at how many employees or shop owners have no idear about the laws that govern animals in a store and how many will just sit and stare and not even make it an issue. We find that the majority of the shop owners will always ask if our dog is friendly.
We do, however, ensure that he does not go into places where there's obvious signage and when there's food being sold. However, it doesn't hurt to ask for permission. We've been doing this from day one and since then, there's been a couple of mini marts in our neighbourhood that let us bring Kairoe in.
Big box chains like Best Buy and some Block Busters will allow pets and many Home Depots - even though they have signage will allow pets in their stores. One large retailer only requested that we carry our dog. One of the benefits of having a medium size breed animal is that people think they're cuter and not so ovebearing.
If we need to post him, we wouldn't dare leave him for more than a few minutes, nor would we keep him out of sight whilst in the store. We live in a very busy neighbourhood with people all around and quite frankly I trust my dog to not bite. It's the reason why we let everyone touch our dog - tail and all, and a reason why we do daily bite training….
With regards, to taking risks...it's pretty much the same as leaving your bike unattended, it's the same as leaving $4000 worth of camera gear at a museum coat check because the museum doesn't allow cameras and it's the same as leaving a bunch of show dogs in x-pens at a specialty...