If you go and see a L you can find out EXACTLY what leaving the marital home may do. I believe it may harm your sitch but I am not SURE. I don't think you can rely on your arrangement that you will leave and then later move back......judging on your W's behaviour she may change the locks as soon as you go and claim abandonment or something. Get anything you are proposing doing checked out and notarised officially and signed by both parties. DO NOT TRUST HER.
Also a L will be able to tell you how to get into mediation. That's not to reconcile but to work out the finances etc. I think that will come as quite a shock to your W. Above all protect yourself and your children. As for the mobile phone.....her reasons stink....if she picks up the phone and sees it is you that is calling all she has to do is hand the phone over to your D to answer if she doesn't want to speak to you. How will you calling her phone be keeping an eye on her? Have you got it on some sort of tracker? My guess is she doesn't want someone she is with knowing you are calling her. Maybe someone she sees doesn't know she is still M'd?
Protect yourself.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength