@Japanic2012
If it works for you you're clearly doing it right! :D
Yeah, mine don't participate in any organizations, don't have jobs, etc. One (Super, her mom is a caster) had access to Potion of Plentiful Needs, which was a huge help, and the vampire didn't need to sleep so she went out dancing with friends a lot because I found her Fun was the hardest thing to keep up. Higher Research and Debate means faster homework completion and a generally easier time; I'd consider 3 an absolute minimum.
I hear that participating in organizations actually boosts your grades, but my Sims all live at home and... *shrug* Living at home helps with avoiding the awful "unbalanced meals" moodlets that I hear the dorm encourages. Keep their needs high and avoid negative moodlets!
Living at home: Basically, one lived with her mom, one lived with her older sister, and the broke vampire was broke because I started playing her as an orphan teen, and she'd never had a job. She got enough starting cash that I could give her a terrible house with a coffin, a bookcase, the cheapest couch, the cheapest TV, the cheapest computer, a desk for homework, and the cheapest bathtub. (Vamps don't need toilets or kitchens, but require a roof.) Oh, and an aquarium, since those are a source of cheap plasma packs if you don't have a frog breeding program, or run out. 😉 After that it was all collectables and gardening (found flowers).
That said, yeah, my experience suggests that you get dinged a full letter grade for every time you go to class and don't take notes. Yikes. Yikes yikes yikes.
Oh! and I second Japonic2012's "enroll on Friday." I have them spend that weekend doing all homework and working on any presentations or papers before class even starts.
[another edit, sorry... I DO have mods, but nothing crazy. MCCC and bugfixes, most on the "hero approved" post.]