The only way to have a relationship with the BPD is to be a really strong male, have a very very thick skin, be prepared never to be loved the way we view love, be indifferent to her behavior, set some guidelines such that if she does not behave she knows you are ready to walk away at any time....and sometimes you need to walk away with bad behavior. These women are disconnected...they may one day chew you apart or love you to death the next day its as if nothing ever happened.
Also, no matter how much she tells you she adores you....as soon as you start reciprocating affection and getting close...they pull away for fear that you will abandon them. Sooo, they do a pre emptive strike on you first. Then they go away and slowly come back as if nothing happened. With these women you can not just bust there balls or punish them for their behavior. When they start coming back...you need to be indifferent to them and not show how happy you are to see them . You sloooowwwly let them back in. You can not show them too much affection or love,...or it will scare them.
If its worth the hassle...this is the only way to deal with them and be prepared for infidelity issues, be prepared to have her win almost every silly argument that is not worth fighting for because they always think they are right, and be prepared for a lot of grief. They might leave you and then when they get dumped from another guy who thinks she is crazy...they come back again.
Most people do not want to deal with this craziness. DO NOT TRY TO CHANGE THEM....they can not change.
Again, you need to be strong and be ready to deal with all her bs without letting get underneath your skin. I say, look at it as a learning experience and a challenge....and keep a few more plates to keep you entertained when she is not around.
Oh...one more thing...I do not know how well absolute no contact works with them. No contact is really just a way to get out with a little dignity and never to expect anything from them...its a way of getting out. With her...we will call it modified no contact. You might approach them after a week or two and find that they might be receptive only because in their little brains they might be going through there nice happy phase and forgotten how horrible you were. Then, after given her the permission to contact you....proceed on your own terms and make her work for it little by little.
These are interesting little creatures....things are black and white....push and pull....yes and no.... one day they love you....next day they hate you and they forgot they even loved you....there is no grey zone for them and there biggest fear is to be abandoned.
Good Luck....Abe