Having couples therapy may prove useful.

I think you need to set boundaries. There's clearly a lack of respect from her end, from what you've shared. Being trusting is hard, but needing to have access to your phone, while being protective of hers, is unfair and suspicious. Platonic opposite sex friendships are possible, and this subject should be explored with compassion and built trust.

I'm going to give you my perspective on her diagnosis. It's not your job to label her. Even if she ticks off all the boxes, at the end of the day, that's the job of a professional. What matters is your approach. How you handle the situation, is the only thing that matters in fixing the issues in your relationship. Calling her pwBPD doesn't make your point more or less valid, but instead causes friction, as BPD is a mental disorder and it seems like you're using it as leverage. Her perspective on a situation is valid in her mind, BPD would only be effecting how she reacts in regards to that trigger.