I feel your pain and wish I could take it away. I have all the same questions that you have, except we do not have children. WE have however been through two deployments and other life changes, so I'll never understand how he picked OW over me for these past two months...
I also understand how you feel as if pursuing will only push him farther away and I'm having a hard time with that as well. Up until a week ago (when I found out more about OW), I was very good and did not contact him for a week (not even about the dog). Now, I'm jumping back on that bandwagon and am going to try to go dark from him.
M: 27 H: 28 T: 8 yrs M: 6 yrs Sep: 2/18/12 (I have no feelings for you!) EA/PA Uncovered: 2/26/12 H introduces OW to his fam: June H moves ALL stuff out: July