I have some answers for you
1) the passport issue: If you can't get him to sign the passport, they have a form you can get, that you record when you asked him to sign the document and when he refused. It is a little tedious, but you can get one from the passport office. I have sole custody, but still needed his signature to get a passport, my sister's husband wouldn't sign which is how we found out about the form available at the passport office. No matter what you will need the long form of your child's birth certificate - it is stated right on the passport application form .
2) Not having an agreement yet - If you can get a letter from your ex signed that you have permission to take your children out of the country that would be best - though personally I have never been asked for any documentation beyond a passport for my daughter - we do have the same last name. Another option would be to have a lawyer draw up something for you, this is pricey though. (but you could have it dated for several years)
Finally I have taken my daughter out of the country 4 times, I have never been asked for my custody papers, we simply go through customs together.
My ex was asked for the letter while they were switching planes in the states, but they have different last names.
Coming back really isn't the issue, it is leaving the country and going through customs in the states. Coming back when you go through Canadian Customs they just want to see the passport and paper work.
I hope this helps you. Remember there are lots of us out there, who have to deal with this too.[/QUOT
From the passport application
Both parents are requested to participate in obtaining passport services for their child and to sign the application form. The other parent may be contacted. To avoid possible delays, we strongly recommend that you provide a long-form birth certificate showing information on both parents.