If I were completely confused as to a girl's interest in me, would it be wise to casually ask the girl's friend (roommate, specifically)?

A girl seems to have interest in me...she'll come to me for shit related to a class we have together, when she clearly knows all of the stuff. At the same time, I still get this friend vibe; I don't feel that she actually wants to hook up.

I'm feeling as though if I knew whether or not she liked me, I could actually pursue that. As of now, I don't really see enough indication, and would probably just cause awkwardness.

No, you don't. You go to that girl, and you ask her to go for coffee with you, or whatever. Then, if she says yes - then she has relative interest in you, proceed from there.