What is the policy of using a business building as a stop? Does it need to have some architectural or cultural value?
A business building is not ineligible by default, but you will need to provide some evidence why it is a Point of Interest (socialize, explore, exercise)
For example: popular restaurant (socialize), a gym (exercise), shopping mall (explore)
There are a lot of ways a business location could be used as a wayspot. Does the business itself promote exercise, exploration or being social? Some examples might be a great restaurant, a gym, a gaming location, a place to take classes, or a hobby shop. Other ways the building could meet criteria is if it is historic, or has famous architecture. And anything on the premises could potentially be submitted, like an LFL or artwork.
I don’t think I have shared this on this topic yet. Here is a link you can bookmark about the criteria:
Be sure to read all four sections there, and come back with any questions.
I’m fairly certain that the category list is some generic “industry wide set of categories” (for some value of “industry”).
I suspect that when Niantic was working hard to get all of this data generated/collected, that bit of extra metadata would help add value.