re: Changing flight booked through travel agent

That's understandable. I guess that is where booking direct from the airline would give you a little more leverage. Even then, if your delay would impact your connection they would usually help out in any way possible to get you on the plane- especially with an international flight.

We were delayed out of NOLA a few years ago and were going to miss our connection in Newark to Dublin. They allowed a handful of us to wait at the front of the plane in order to get out first and they called ahead to hold the plane. We ran through the terminal and made it to the plane. They held the plane at least 30 mins for us.

I wouldn't change, but that's just me. Peace of mind is a powerful thing, especially if you aren't that familiar with international travel.