Every part of your sitch is like me revisiting mine. It got to a stage where W hated me soooo much, that she would have done everything and anything irrational just to get rid of me (even hiring a hitman.........well maybe not as she probably couldn't afford one at the moment )
I too had problems with the custody thing, and splitting our assets etc etc.
But since going dark, probably over the last several weeks I have noticed a huge change in W. She is more respectful and agreeable in everything, including custody and asset sharing.
Also, the more you react to what other people may or may not be saying (eg MIL) the more you look like the tyrant in your R, and the more W will brainwash herself into thinking this way.
Believe me, as proof in my sitch, I have noticed that since going dark, all the people that supported her in leaving our relationship are starting to drop off, due to my W not really wanting to interact with them. I am sure the fog is slowly lifting in her life, and she is slowly starting to realise that these people may have been wrong.
So I would def go dark, and try not to say anthing to anyone about how you feel or what you think of your W and what she is doing. Also keep your S out of everything, protect him the best way you can. Kids know exactly what is happening and who has been the cause without you telling them. My DD has even told me (with no prompting) that OM has destroyed our family...........because she can remember him "sniffing around" when I was away for work 12 months ago.......two months before the bomb.
I hope I haven't confused you even more All my best, AndyV