Welcome to the forum.
I wanted to address this. When I see the word “categories,” I like to make clear that the categories you are asked to choose from when submitting from Pokemon Go have nothing to do with eligibility. In fact, many things listed there are strictly not eligible, like elementary schools. If you use the Web Submit option, there is no categories question. These are just data points.
Second, what points of interest did you have in mind that should be accepted in rural areas that wouldn’t be acceptable elsewhere? There is no list of things to accept. Just the criteria of a great place for exercise, exploration, or being social.
I am curious if you review nominations? It can give you great ideas to see what others have submitted. There is a topic here with a lot of ideas: Tips for Rural Nominators