Kudos to you Mik! Without people willing to get into motorsport at grass-roots level, motorsports cannot exist.
I did flag marshalling at Barbagallo Raceway for a few years and loved it. Apart from the competitors, flaggies are closer to the action than any other official. I got involved and passed my CAMS accreditation via the local flag marshallers association and had "on the job" training with a senior flaggie. I'm pretty sure that goes for all officials at a meet too.
If I can give one piece of advice: Be vocally intorerant to intra-association politic bullshit. I wish I was, cos it's what killed my passion for it. Nothing worse than factions forming within a club or association, that gets to the point of killing the fun of a meet.
Oh, and reconsider if you're thinking of doing scruitineering. Then again, you are used to being a pariah... lol!