Kit, the very fact you were introspective enough to be worried if you were borderline, is pretty good evidence you aren't. They don't give a fuck about anything, or anyone bar themselves. At least, not outside of the context of making sure whoever they are attempting to suck dry is obedient and compliant sufficiently to have their current victim/s do whatever it is they are intended to do in order for the BPD piece of shit to bleed them.
Dirty, nasty, sneaky, and the most thoroughly poisonous, noxious creatures bar child rapists and killers you are ever likely to come across. If ever you need to deal with one, just remember, they have NO limits, and will do whatever it takes to attempt to get what they want. They are impulsive, severely mentally unstable, conniving, lying, sneaky and downright dangerous.
So if you have to interact with one at all, and you know or find out what they are, use them for whatever you want and then dispose of them. No, that isn't very nice, but it is what they will do to you given the chance, so that merely insures you get in there first and the tables are turned so that the borderline is the one on the receiving end, instead of you. And don't feel guilty about it either, because if they haven't done something horrendous to you personally (YET!) then you can bet your left gonad that they have done it to many other people.
Borderlines are nothing short of a poisonous disease, that needs to be cured (preferably by smoking slowly over hot coals after being skinned and salted), and failing that, stamped out and cleansed from the face of the earth, like a dog turd being bagged and dumped in a bin. Because they are exactly that. Only difference is that kind of dog turd walks and talks as well as the usual stinking and attraction of swarming bluebottles.