I personally don't like this idea. Has too much potential to go wrong, and with the rewards thing, has a potential to screw over more casual or otherwise "uninteresting" players, or those who accidentally end up doing something they shouldn't. (Here I got a month ban for accidentally doing something stupid, but I can live with that tho)
With MMOs, you do tend to get longterm rewards (or ability to get items that'll never be available again), but mostly these items are a badge of honor and not gamebreaking. This is making a realworld effect, which has more chance of alienating the playerbase.
Also what happens with "controversial" players, like trade trolls in WoW? For me, I don't mind them if they're not overly spammy, but others hate the whole trade-hanging crowd. Also you get people who hate swearing, and others who don't care... so it's hard to say if muttering the odd rude word here and there suddenly it all falls apart because you were in the "touchy" crowd :/.
Also I don't consider that the hat designers as necessarily the "good" players - yeah, they did something good, but it's only something that a subsegment of the gaming population could've done (I'm bad at ideas lol).
Also I read a comment in this thread about "yeah, I'm good at getting conversations going"... if they got a reward for that, why should I be penalised for not being able to do that? I tend to be unable to start conversations (personality flaw I do try to work on), but I'll join in if one's going... so I'd be effectively made worth less for something I can't really avoid.
Also there's another side effect that I've seen in certain freemium MMOs - rich people become jerks, because they can. The money is immaterial, so they just abuse the system. (In MMOs with char-improving items, they're usually priced so that most people sit at similar levels, but there's always exceptions).