Actually, it depends on where you are traveling - if you are traveling to the Caribbean, all you will need is your Nexus card; a passport is not necessary if you have a Nexus card. I used my Nexus card all over down there without problem.

As far as a name change on a passport, it is free to do so as long as it's been less than a year since your passport was issued. After that, there is a fee. You do have to submit original documents as proof of the marriage and it involves sending your passport along with a federal form to get the change.

I, personally am encountering some of these hassles myself. I am an American citizen who married a Canadian on Dec.30, 2015. There does seem to be a definite order to the chain of events that is name changes on all documents. I spent the day today trying to do this - Social Security was the first step. After showing our legal marriage certificate, the SS office said it would take until midnight for the federal gov to recognize it - then it will be another 12 hours before the state of Michigan will recognize me so that i can then apply for the change on my driver's license. Once that's done, I will be able to switch over banking and then apply for my new driver's license. I was told I'd need that in order to get an appointment to finish renewing my Nexus card at the border. We will see - everything seems to take three times as long to do than what I was told!