Kind of going to say something similar to Bim_bam here. To me, most of the things you're planning to do as a Head Administrator (Training/educating staff, helpfulness, forums activity) seem to be actions you already have the ability to take action on as a Super Admin with the exception of training other SA's. Not that it is a bad thing to state in your HA application, just that it'd be appealing to also have additional things that you can contribute with.
Basically try to explore more on what it is that you can "additionally" contribute with by becoming a Head Administrator.
Best of luck at the meeting on Sunday.