A couple thoughts have occurred to me as a read (and reread) this thread. The first is that you should not worry overly much about what a winning CA submission should be like. We have won three RCAs, and while two of the submissions were fairly similar and standard, the third was very different. We have had a couple of submissions that by almost any objective criteria were better than any of our winning submissions, but just not the best at that competition.
We do spend a significant amount of time with the presentation team trying to craft the best possible presentation. That is a useful skill to have, and it draws in many team members at one point or another. But the rest of our submission is largely about our own appreciation for and documentation of our history. It helps us stay focused on the core mission of the team. Like any team we have a tendency to think about activities as "robot stuff" and "Chairman's stuff." The submission serves as a reminder to everyone about what our core mission is. (OK, or second core mission after having fun.

) We try as much as possible to push our outreach and other such projects away from the build season. This keeps kids from getting too burned out. We have been doing more and more of the documentation and other work outside of the build season. I am aiming for the time when we get the Chairman's submission largely done before the build season starts. Doing at least some of that work on the submission in November and December is a good way to get people psyched up for the season to start.
The second, related thought is do not look at the CA submission in a vacuum. Most FIRST teams have to do presentations to sponsors every year. Your Chairman's video, essay, documentation and presentation can form the basis for these presentations. They should be used this way.
The final thought is this. When you decide what kinds of inspirational activities to do, think about what students on your team are enthusiastic about. Some of our members started a STEM sisters club a couple of years ago. They were/are really passionate about it, so it is easy to sustain. We have a number of kids who love to mentor FLL, so that is another program that is easy to maintain. We frequently get asked to help with projects in the school and community. When I am asked, I usually start by finding out if there are any kids interested in taking on the project. For example, our theater department wants a remote controlled "boat" that will wander the River Styx in a play and our track teams wants a rain and wind shelter for the pole vault pits. Both projects have some enthusiastic students who are interested in completing them. We have a couple of other projects we have been involved in over the years that took forever to complete because there were no enthusiastic students to see them through.