I don't know why proving alcoholism would be so tough; I tend to disagree. There are witnesses in both of your lives -- including your children -- that a court-appointed evaluator could easily determine. The BPD would take a psych evaluation, which is costly, but not THAT costly.
I'd encourage you to look up DCBHM on his thread (over on the Infidelity forum), as he is VERY sharp on the legal stuff, including the psych eval stuff.
