Hi Tin man,
Welcome and hello

I'm so sorry for what brings you here, and glad you found the site. You fit right in here!
People with BPD tend to have no real sense of self and can take on the qualities of people around them, and lawyers and therapists can do a lot of damage if they have their own issues. How completely unprofessional and strange that the therapist wrote you letters! That is just I know you have a lot going on right now, but have you considered filing a complaint with the professional association in your area?
As for entitlement and deception, that is unfortunately standard operating. Being emotionally immature, she will probably be 100 percent focused on getting her needs met, and that can be exquisitely painful to deal with when it's linked to legal action, where the means justify the ends.
Have you read Splitting: Protecting Yourself While Divorcing a BPD/NPD Spouse by Bill Eddy? It's the Cliff's notes to these high-conflict divorces. That book, and this community, will help keep you sane. You already have a therapist and that is soo important, especially to help curb any codependent tendencies you might have to self-sabotage.
For now, focus on having good, healthy boundaries. For many of us, this typically meant that we felt a good deal of guilt, which has to be set aside. Doing the right thing for yourself and the kids is critical right now and feeling guilt will only help your wife steam roller the family.
A lot of us noticed that the FOG lifted (fear, obligation, guilt) after a few years post-divorce, and it can feel like our old selves are almost strangers to us as we get healthy and teach our kids how to be emotionally resilient and mature.
Where are you in the divorce process at the moment? Are you living together? What kind of custody arrangement is in place?
Again, glad you found the site. This place changed my life. The people here understand what you're going through and the advice is priceless. You're not alone.
LnL