As long as he has a 2nd class medical and the plane has a 100 hr
inspection it should be fine (and doesn't 'transport" people, i.e
returns them to the same airport they left). His insurance would
probably be pretty high though. Doesn't count as dual or insurance or
anything though. In a practical sense, CFIs often have a hard enough
time getting business, this guys going to be working hard.

-Robert