Trading merit is against the forum rules, so doing such will have severe consequences. Although I have never received such messages but I will distrust any member that sends such personal messages to me.
Trading merit is discouraged by forum community because it helps shit posters, farm accounts to rank up. After they rank up from merit farming, they will spam in forum and makes the forum worse in quality.
Trading merit is not prohibited by forum rules.
- Giving negative trust for merit trading and deceptive alt-account use may be appropriate, but you should use a light touch so that people don't feel paranoid.
If the "gaming" takes the form of strategically sending a lot of merit, creating sockuppets, and stuff like that, then no. That sort of gaming might get me to blacklist people, in fact. But if it looks more like politics, then that's OK, and that's what H8bussesNbicycles's thread looks like to me.
The current status quo seems OK. If you have to pay $20 per merit plus a risk of getting red trust, then that's a situation that doesn't concern me at all. I'm not going to lose sleep over people going to ridiculous lengths to buy merit, since only a small number of people will be willing and able to do that.
As long as merit sales are a black market, I'm happy, since that makes it far more difficult and expensive to buy merit. If that's the case, then the small volume of black-market merit trades don't themselves bother me much, and I think that it does more harm than good to get too witch-hunty about it.