The other thing to remember, and Bob can correct me if I'm wrong here, is that the Advisory Board was originally envisioned to be made up of highly knowledgeable martial artists in different areas/disciplines, to answer specific questions about specific arts that might go beyond the "regular" readership. It seems to have been taken as an Advisory Board for the details of the MT forum, rather than a martial arts advisory board, though, which isn't the way the area reads… but, in either case, it's a position that reflects acknowledged expertise in particular fields. Safe to say, and, at the same time, sad to say, many who may consider themselves such "experts", well… aren't. As a result, it is, as Bob said, an invitation only type of position.
So that leaves us with how to be as involved as you can? Well, luckily, that's quite simple… and doesn't require you to be picked out above all others, and elevated to the lofty levels of Advisor… all you need to do is to engage in the threads. Post questions, start topics, welcome new members, contribute to the discussion… being a Supporting Member is, of course, highly appreciated as well… of course, individual circumstances play a part in that, which is understandable, but if/when you can, great! If you are seen as a positive, valuable member of the forum, you might be invited to become a Mentor… which, I feel, is more in line with what you're thinking of… and from there, who knows? Maybe even President!!! Or, you know, just a fun guy. The sky's the limit!