My L and I poured over the details of the process in my particular county, and she thinks proving the BPD and alcoholism will be difficult and very costly. The retainer is 5k, but the cost of this could skyrocket to 6x-10x that amount.
Her prices are about spot on I think, but it concerns me that she is saying it will be difficult and costly to prove alcoholism and BPD. Your 17 year old is def. old enough to be a witness. She was on medication in the past for bpd isn't that right? Before you hand over a hefty fee to this L, maybe you should interview another L or 2 and see what they say about your case? This seems to me to be very critical in your case, and you have said also your W is abusive to your children when drinking didn't you?
RE: The MC go if your L advised you, but in my experience, and others I've seen here, they have to have both spouses willing to work on marriage counseling. If your W is not, then it will not be possible. I would not participate in divorce counseling if that's what they would like you to do, unless you are interested in D as well, and don't see how that could be used against you legally if you make that clear.