to start this is the 1st time i have realy tried getting into an RTS game, for the last few years i have been playing an MMO called dofus (www.dofus.com) which had various connectivity issues over the years, generaly compensated with ingame items etc the longest downtime was for about a week, and resulted in a double xp week compensation (that incidentaly killed the servers too). the point being when things went wrong and people were unable to connect the communities turned nasty, and always demanded some sort of compensation.
what has happened so far in DG is that the connectivity has gone from complete and utter crap to something vaguely resembling a playable game if your running the beta over the period of 2 or 3 weeks.
being the internet people still feel obliged to shout their opinions on balance, OP'd classes etc after only a short period of limited gametime.
Understandably people who havnt even had a chance to play the game online get quite miffed at suggestions like this showing up quite possibly recommending a nerf for their favourite character based on SP experience. My personal opinion is that there shouldnt even be a suggestion forum untill a month or so from when the game is working correctly, but hey im one of those weird people who thinks you shouldnt voice an opinion based on a passing glance of something you havnt taken any time to understand or research.
There can be and are communities that are pleasant to be a part of, and which can be moderated without making people feel like the live in a police state, the single most effective measure i have seen in any forum though is employees responding & posting in threads, almost regardless of what the response is it either calms debate or leads to a more amicable end to discussion (unless its something like "the connections work fine for us, its your problem")
perhaps the karma thing could go negative resulting in peoples posts fading to a more grey unreadable text giving them a very clear indicator that they are pissing off too many people (negative karma wearing off over a few days maybe)