This makes me happy I opened an account a few weeks back.
Here's an idea. The one potential snag I see is the timing of mission launches. People are impatient, and won't like waiting for half an hour for launch. How about a system where a player can "reserve" a slot in a mission sometime in the future, and then go fly in another arena. Five minutes before "launch", he gets an alert from the server that his mission is preparing to launch.
The other key will be ensuring the system brings players together. Like in IL2 or a good scenario, a good mission setup brings players near each other at the critical place and time so a fight can happen. If you can find a way to automate that via a host process, you could have a winner.
The danger here is how to prevent milkruns or empty missions. I proposed a system for WW2OL missions a looong time ago that might work. Create a "Goals" structure ... a CM or HTC employee logs in, and pulls up a GUI to set short-term goals for a side. These can be fairly broad and based on time. A 48-hour goal set for one side might be, capture these 8 fields. With this goal laid down, now the auto-mission system can generate a slate of missions in support of that goal. Or, a player CM can do the same.
The missions would be generated for both sides based on that goal. Since the serve knows the goal in terms of objective and location, it can design automatic leap-frog missions to reach it. And design automatic "defense" missions for the other side, to bring people together.
For example, let's say one goal is to secure two or three fields. The server randomly picks a field from the once designated, and makes four missions for the next hour: one is Offensive CAP over the target area, one is Bomb Strike of the target. On the other side, it creates an Area Defense CAP mission near the target area, and an Area Recon in the area surrounding the target. These four missions are designed to put people in the vicinity of the target at the same time. the host monitors progress toward the goal, and creates similar missions as needed.
Capture doesn't need to be the only goal type. Other possibles are, Interdict Supply, Control Air Space, Defend, etc. anything that a host process could look at, analyze the arena, and create an automatic slate of offensive and defensive missions.
Goals could be short-term, say 12 hours, or long term, say 48 hours. They would provide a framework that could run on autopilot, at the "Goals" direction of a CM. Have a maximum of one short-term and one long-term goal per side.
Take those 4 possible goals per side, the automatic missions being generateds in support of them, and you got yourself a non-stop war. Allow ranking players to also post missions in support, and use the same server AI to post a complimentary defensive mission.