User blog comment:ChishioKunrin/Is Qrow a weapons teacher?/@comment-24267097-20151022171710

for the questions at the end:

Those who fail to be accepted to huntsman academies will either have to reapply or choose another career path. Like how college is dealt with in places without free tuition. I would assume most would be able to be able to operate in things like Ironwood's army, Junior's goons, White Fang, etc.

Most likely, but not universally. I for example suspect that Penny did not go to a combat school, as I think that Ironwood wanted to keep his ace in the hole secret.

Almost certainly as being in the reserves often provides job security for those worried about such things.