FIB, get a new Guardian. They are supposed to help you not hinder you so get your lawyer to request a change of guardian to another one who will get off their asss and help you here.
Stop making excuses for all of them. Hold them accountable for their jobs and what it is that they are supposed to be doing. Don't call the GAL to discuss counseling for your kid. Call the GAL and tell them when the appointment is and with whom. If they have a problem they will sure as hell call back.
Did the GAL come out and meet with the kids yet? Visit their school or day cares? Met with you and the STBX? These are basics to their job, hold them accountable.
Not for nothing Frank, but it's time to start wearing a wire. Record some of this insanity. Go to the lawyers with her voice on tape calling you satan to your kids. Put the screws to her dude.
Your marriage is going to end either way, she doesnt have to be a bitch the entire time and at some point you have to stop letting her. I know you want desperately to be the good guy, but there comes a point where it's time to be a little tough yourself dude.
Strength and Honor also means being strong enough to honor your kids by standing up and saying enough is enough.
I love ya bud, I love your heart and your compassion, I love that you have taken the high road throughout. You have done your part my friend and no one is going to ride your asss for standing up here and saying enough is enough.