DefinitelyDressage.com

get paid? Ballpark figure.

and does a schooling show judge HAVE to be an L graduate?

I have judged schooling shows and not been an L graduate, so no, it depends on the show manager and how much the competitors want a qualified judge.

The amount can vary from volunteer ( four h etc) to 200 to 250 for a reasonable day.

My group used to do an annual schooling show and we typically employed L judges and typically paid $200, plus booked a motel room and picked up their dinner tab. And any food they chose on the show grounds. One judge became enough of a friend that she would stay at my house while I slept on the show grounds.