Завуч = заведующий учебной частью, lit. teacher responsible for study and learning section (higher authority than just teacher).
Зауч - might be some student slang, but this spelling is incorrect, one letter is missing and it looks very informal.
Instructional aids - probably they exist on pre-school level (still they have some pre-school working qualification), but there's no popular name for them I think (though of course there's some official name, but in an elementary school it's just ONE teacher in a room doing all the job).