No one expects you be an expert in every aspect of your application. In some cases, yes, but we prefer you pick just one, especially starting out. It can be tough enough just finding the time to contribute to a single conference. This also depends on the amount of traffic in the conferences and the strength of the existing Moderators. There is no fee for being a Moderator.
Moderators participate for two main reasons.
First, it's fun and satisfying to help your fellow collectors. Sounds a bit corny to say it, but it's true. As well, MCAH works hard to acknowledge your contribution. Your name is prominently displayed on a Moderator menu in your conference, which links to your entry on the Moderator Team Page. There you can tell the world all about your unique Militaria expertise.