At one point I felt there might have been a mutual attraction but I never acted on it.
this may be one major point of confusion.
its difficult (at best) to have a friendship, or be roommates with someone you have conflicted feelings about.
how to handle the relationship probably largely depends on working through those feelings (no rush!). if i were trying to improve a friendship, it would look very different than if im trying to improve with someone i have feelings for but want to remain friends, and either of those would look very different than if i were trying to become romantic partners with a friend.
an important point is that when it comes to having a relationship (of any kind) with someone with bpd traits, confusion is really your worst enemy. your friend, whether consciously or unconsciously, will pick up on this, and be even more confused than you are. the boundaries will become that much more blurry.