Pat, I am not familiar enough with the Mission Editor to create example missions of the balloon defense and escort mission types. I need to spend some time on that to learn it.
In the meantime, is it possible that some of the canned mission scenarios that come with the game would serve? Looking at the Missions for the Albatros D.III, I see it has one, "Call from the frontline", that is a takeoff and then defend a balloon mission.
Similarly, for the Albatros D.Va, there is one called "Observation escort", which requires a takeoff and the mission is to escort a DFW. The Camel also has an escort mission. The Sopwith Pup has a balloon protection one as well.
I'm just scratching for ideas to help here.