I've had maybe one or two PMs from Merit beggars in the past. Just report them, and forget about them.
One thing that I will suggest to merit sources. Please look at recent post history if a guy appears to be trying. I see that some members are active and productive members of the community, but they don't receive any merit. This is because they don't make any of those outstanding posts in the high reward topic threads.
That's the thing: merit isn't only meant for outstanding posts. Being "outstanding" means it receives more merit, but posts only need to be "good" to be merited.
Remember that Merit was meant to discourage spam, and if someone isn't spamming, they're already far above the forum's average.
On a side note: You're very active rewarding merit, but you haven't left any trust feedback at all. Is there a reason for that?