It's hard to wonder if perhaps I am narcissistic, or at least on the high end of the spectrum. I worry a lot about being a covert narcissist.
Not to hijack, but so what if you have narcissistic insecurities? Seeing this is not a death sentence, its a window into our own psyche. The Internet stigmatizes mental illness and it becomes a black label. But that is not what it should be at all. We don't need to buy into that, anymore than we should believe the happy world according to Facebook.

If you have narcissistic insecurities and embrace them, you can then start working with them. It's not unlike an introvert working against their natural tendencies and becoming a dynamic public speaker.
People with BPD aren't attracted to the narcissistic insecurities, they are attracted to the strength and drive - good things about narcissistic tendencies. This is just the same way that people are attracted to BPD tendencies for their deep emotional expression (not the attachment struggles and impulsiveness).
"Gnothi seauton". Know thyself.