So far, my Sim is doing well for the elective subjects (1 elective subject each term). I did the same thing, attending classes (which either I get them to listen to the lecture/taking notes) and all other things that you've mentioned. Just wondering, have you ever email the lecturers asking how well are the Sims doing in the particular subjects? And for studying, I normally get my Sims to study a few hours before the exam, so that they get the optimum moodlet while attending the classes or the final exam.