Yes, you have to be actively participating, but probably don't have to be as active as me for instance. If you're seen as a helpful and rational person I guess it will help though. Reporting lots of posts but not actually posting much probably isn't very good. You also might be in a tricky situation or grey area with farming and selling accounts. If you sell an account and it goes on to spam or scam and it's tied to you somehow I don't think that will look very good. And what do you mean very special reward? From a user or the admins? (though maybe you don't want to say).
I will PM it to you. It was from a user, although the user is somewhat close to the admins.
I think you are right about the farming accounts, although I checked maybe ~1.5 months ago and none but maybe 2 or 3 out of 50+ received any kind of negative trust/scam accusation, although I don't think the whole bayuo/zedicus case is helping my cause.