Well you are most certainly not alone having these ideas and they definitely don't make you a bad person. Yes they may seem kind of crazy and very dramatic, but in my opinion they're "normal" considering what people with BPD experience, and they seems to come from a place of desperation for love.

I've spent a lot of time imagining how I could fake my death or disappear, and how people would react. And I have also imagined ways I could simply just get close to death and get a lot of love right before the end of my life, and so, I know this is terrible but I've strongly wished to get cancer during some dark periods in my life.

This may seem harsh but I feel like in general in the world, a dying/dead person's life is more glorified than it ever is during their lifetime, and they receive more love and appreciation on their death bed or at their funeral.. But of course I am being very negative.

I wish for you that you find people who make you feel very loved, and I hope we all manage to celebrate the lives of people we love, our relationship with them and give them all the love we can.