[Moriarty]

The way I see it is this:

We have 9 careers. In order to achieve in any career you need to study it first. Anyone can do a job but to excel at it you have to be trained.

I like Marlos 3 lvl idea so after completion of all current school classes you would graduate onto college/university pre-career courses

These courses on completion would give a better return on career points spent in your given field

Engineering - Structural engineering degree course - Degree, Masters, PHD (or US equivalent)
Martial arts - Dan lvl training - 1st, 5th and 10th Dan
Military - Military training - Cadet, Soldier, Officer
Construction - Architecture - Degree, Masters, PHD (or US equivalent)
Athletics - Sports scholarship - Degree, Masters, PHD (or US equivalent)
Medical - Doctorate - Degree, Masters, PHD (or US equivalent)
Science - Biogenetics - Degree, Masters, PHD (or US equivalent)
Politics - Govermental studies - Degree, Masters, PHD (or US equivalent)
Manufacturing - Product design - Degree, Masters, PHD (or US equivalent)

Basic requirements for the 3 lvls would be

a) completion of all school courses
b) lvl 1 - Career lvl3, intelligence lvl6, reputation 3, lvl22 character
lvl2 - Career lvl5, intelligence lvl8, reputation 4, lvl30 character
lvl3 - Career lvl7, intelligence lvl10, reputation 5, lvl40 character

This would give a player scope to really hone in on one career yet for a player playing over a long period of time the ability to master 2 or 3. For the player that plans to play this game for years and years this would give him 27 new courses to study.

Actually studying the course should be the same as the classes are now and run in the background as long as you are active. every day you log in adds +1 to the days studied. after 60, 90, 120 days. You graduate and the returns for each course increase. Where construction currently returns 4 strength I envisage it increasing to 6,8,12 a 50% increase on them all at every lvl.