I still have more questions than answers myself, but my take on this is that we will now have 3 versions of businesses.
Residential (Small Business) is a lot where your sim resides, but where you can combine a business section as part of the lot.
In addition we'll get the lot category Small Business Venue (Small Business) where a sim can have their business if they prefer running it away from the home lot.
Both these lot categories are new with the B&H EP. They will not replace the old community lots that will still come with numerous business related lot categories. So, if you download a lot it makes a difference what lot category it is. Older builds on the gallery will obviously be the old lot categories that are not owned by a sim like the new categories are, so the game will not assign any new owner to that clothing store in your example. In the future, when simmers upload lots with the new category, they will be lots including a sim owned business an d moving on a sim gives the option to also run a business. I don't expect the gallery to carry over the detailed business concept settings, including customers' activities and target group etc. I think this will be possible only if the lot is occupied by the owner, but I might be wrong. So, the builder would probably need to upload the small business lot with a family living there, to provide a business concept. But I expect the room dedication to either private, employees or business can be set by the builder, even if the lot is unoccupied.
I do not know for sure that your played sim living elsewhere can go shopping at a small usiness, but I would expect them to. No idea whether employees can serve the bakery, but staff can also be household members (they might be easier to control when it comes to what to cook re skills etc).
