On a more serious note, I think you're taking things way too far- however we don't exactly know how personal the leaked info was, but things are getting a little out of hand
If you have to I guess 1 & 2 are the most you can do before things get too far and, as @(you need an account to see links) said, absolutely pointless.
1) And the point of this is....?
2) Same as above. Overall will you have any impact or make any point? Probably not.
3) You're tampering with something school related. What happens when she goes to the school to see who's been tampering to her account? They'll be looking into that.
4) That is low. And stupid. And even you noted that she wouldn't cope well with the result in the long term.
You're angry, but your response is petty. You're in college. Sit down in the same room and talk it out.
Am I the only one who thinks that deleting random people on Facebook would be ridiculously funny ? Hahaha.
I wouldn't do 3 nor 4 (big consequences), and I guess 1 neither because it's irreversible. But deleting people on Facebook ? She still can add them again.
And well. I think I have to tell you to talk to her too, but I know I would want to get revenge too if I were that mad !
I would take many precautions if I were to tamper with the school account. And even if it did come back to me I would just shrug. What are they going to do? They'll probably just readd the classes and give her credit.
@(you need an account to see links) I would permanently delete any type of sentimental looking conversation, pictures. I wouldn't bother with friends.
My only other ideas would be to knock on her door out of the blue and that would probably end up with me punching her in the face. I'm very passive aggressive in my approaches to fuck with people. I find them more satisfying. I want her to lose something.
It's like converting peoples pets...they'll get them back but it's just a pain in the ass.
You keep trying to justify what you are doing. Don't even bother. It isn't helping anyone at all. It might make you feel good but that's not the point - you would be fucking up her life.
If you want to assert your authority just do it how they do it in the animal world and pee on her or something. Kidding, but seriously I don't really think its worth doing any of those things. I think its all going too far. I'm confused though, did your new roommate tell you she knows something personal about you, or tell it to other people?