Nice post MungoP,
Regarding the three years you mentioned. It was explained to me by an instructor that FSI considers 3 years to be a break even point on employment.
They invest a large period of time having new guys sit in on 2 initials then 2 recurrents, then they prepare their training notes, then practice giving instruction to other instructors, and finally, they are turned loose on "real" students. The process takes 6 mo for a sharp guy with flying and instructing background up to a year for lesser trained guys.
FR