Sending moral support. I went through a situation with some similarities, and I too was concerned that the court system wouldn't protect my son if I divorced.
After reading your posts I was disappointed that you didn't go through with the filing now. But then I remembered all the twists and turns of my own situation and how it wasn't easily solved (either emotionally or legally) and I realize I was holding you to a higher standard than i was able to manage myself!
These situations are so amazingly complex. You are doing a very hard thing. There may be no perfect answer to any of these questions. But I give you SO much credit for facing all the difficulties and looking honestly at your role in all of it.
I hope you can be kind to yourself and deal in some way with all the stress. Again, sending moral support. I hope things become clearer for you soon.