Disclaimer: I'm responding before reading any post other than the OP.
Some of the good things to come about for me b/c of this disorder ( I no longer meet diagnostic criteria, so I'm considered "recovered").
- Highly sensitive/intuitive (this can be developed very, very far with advanced meditation practices [buddhist])
- The positive emotions are as strong as the negative emotions, when I feel joy -- it's JOY JOY JOY JOY JOY JOY

it's immediate, and very contagious, I've been told my smile could light up the universe.
- Being very in-tune with another person can allow depths of intimacy not even imagined by nons
- Being psychotic sometimes allows massive doses of creativity in my life ( I paint, draw and bake/decorate desserts better when I'm triggered because "I" am gone, just painting, drawing, desserting, decorating is left)
- Being more prone to mysticism gives me an "anything is possible" outlook on life. (this may not be exclusive to BPD, I was also dx'd Schizotypal)
- Being eccentric, "crazy", interesting, intense, at least for me has been more of a blessing than a curse, I never wanted to be normal anyway, I'm much more invested in being a me that I can live with and enjoy (another cool thing about not having an entrenched identity is that you get to make it up as you go!)
- You can be anyone you want to be at any time, like anything one moment, hate it the next, so you're always wondering what makes you like/hate things anyway, something very deep philosophically (to me anyway)
I have to go and will add to this later!
Okay I wanted to add a couple things.
Healing requires love, it's that simple. Where it comes from initially is not as important as where it will come from after it's all said and done. Something that comes to mind---we are taught how to love in life by ........ who? Parents? Usually? We are also taught how to be somebody by our families. This somebody may get along in the world and be successful, or a whole range of other possibilities like personality disorders (there is evidence supporting PDs developing from environment as well as genetic predisposition).
So what happens when we're not taught how to be somebody and how to love? It's a swirling mess of emotions, fragments of intentions, sporadically reinforced attempts at being normal, etc.
As much as nons learn from pwPDs, it is still night and day. There is a degree of understanding that is possible, but it only goes so far as you're willing to go in understanding yourself (and by proxy, the entire human condition!). PwBPD are like mirrors--Mirrors reflect, and not everyone likes the reflection---
HTH!! and hope I answered the topic, going back to read the rest of people's posts now.

One other thing, therapy is for creating and enforcing an ego that is suitable for society. Is this the best course of action? What about going beyond the superficial personality to the underlying causes, fix the root causes of "mental illness"... which is the fact that we human beings are living contrary to our true nature and this causes anxiety, depression, mental illness, homicide....