This is absolutely crazy
I can understand the point in having someone occupy the seat when a FO is not in it, but I was not aware that crew are trained in away way in how to operate anything major in the flight deck other then monitoring and switching off, of the APU? I may be wrong it that though!
This kind of situation just makes general aviation safety seems like a joke, when you think that as pax you have no idea how good/bad a job the crew are performing.
Kind of reminds me of the "kid in the cockpit" situation with the aeroflot flight 593. I know circumstances are very different here but its the principle of allowing a novice person at the controls when pax are on it...
I know it would make me very annoyed if I were on it