The north arrow of the compasses will all point to the south since opposite poles attract. I have put an example picture below.
For the horse shoe magnet the magnetic field line will also go from north to south. I have put a picture of this below
The mineral with Mohs hardness would be scratched because the mineral with Mohs 7 hardness is stronger than the Mohs 5 mineral. Eventually, that mineral would turn into dust if you kept rubbing it.