I am just going to give you my opinion on some things in your post above.
She is not giving you mixed signals and she made it crystal clear she wants a divorce.
Either your coach is wrong or that's not what he meant about sharing something you learned. When you said living in two houses negatively impacts the kids. That's manipulation on your part and totally pisses her off.
I don't know why you separate in advance and why you wouldn't try to keep things as normal for the kids as possible. If you feel you must separate maybe wait until school is over.
I think you need to work on validating those conversations and not apologizing.
Vapo is right about the ea and I detailed in my previous post what is going on with her. I was watching the show Parenthood one night and the mother on the show was giving her daughter some advice on marriage. She said the most important thing in a marriage is foregiveness. Your w can't get there right now. Maybe she will someday.
I have been listening to Peter Crone podcasts lately and he explains that if you had the exact same experiences your W had in life you would want the same outcome as her. Life happens exactly the way it's supposed to happen.
