What categories/classes is a Ground Instructor able to instruct on?
The basic ground instructor covers everything you quote.  The only additional privileges you can get are those granted by the advanced ground instructor rating.  My ground instructor certificate just says "Ground instructor" on the front and "advanced instrument" on the back.  No other ratings or limitations.

Things like reading charts, familiarity with regulations, weather information, fundamentals of flight and other required knowledge topics do not depend on category or class of aircraft.  You just need the BGI (and IGI for instrument) to teach ground and endorse written tests regardless of the aircraft the student is or will eventually train in.

The only other benefit to having a ground instructor certificate is that it is required to get a gold seal on your CFI certificate.