Sounds like some type of guest house. I would say the AFCI applies.

Without a doubt, GFCI, and very possibly AFCI

It's more like a recreation room, just called a cabana. Don't think GFCI applies (enforcible) since it is totally enclosed. If it was an open structure, it would.

I suppose you really need to look at the plan but the ones I see are more of a changing room and a bathroom. They are usually not big enough to be called a recreation room.. I suppose it really depends on how rich the people are. There are probably mother in law apartments that get called cabanas.