It seems to me most of the problems started when NSider closed down. All the kiddies that used to bicker on that forum are starting to migrate here for lack of a better place to go. NSider had LOTS of useless spam posts clogging it up. Probably among some of the many reasons it closed down was rampant discussion of flashcarts, ROMs, flaming and off-topic posting.
GBAtemp is a very active board. Most people WILL migrate to a board when they see that it's very active. There's not much anyone can do but report trolling/spamming and have it moderated on a post by post basis and hope the issues resolve themselves through moderation.
A Kudos/reputation (whatever you want to call it) point system is NOT a good idea. I've seen this at other forums and it quickly becomes just buddies rep'ing each other while some members never get the recognition they truly deserve simply because they don't post constantly. It just doesn't work. The people that end up with high ratings start thinking they are better than everyone else and that starts its own vicious-circle of contempt among the rest of the members.
I've seen a few people get "post-restricted" on this site and that seems to work. Once the member was able to post again, that member didn't post like they did before. I feel this is a very good method of moderation.
Another good thing I see is the "Warn percentage". That needs to be used more intensely. Maybe if some of the offenders start getting more warnings, with the understanding that reaching 100% equals a ban, they will chill-out a bit and either post less, or put more thought into their posts/replies.
Personally, I don't mind people just being silly and humorous, that's all part of the "fun" of forums, but flame-baiting, all-out fights and off-topic posting in threads really needs to stop. I also understand people posting one word replies as they just want to feel like they're part of something even though they don't really have anything to say. That's just normal forums activity in most places I've ever seen.
I can't say that I have never crossed the line in my posts'replies, I'm sure I have, but I at least I TRY to stay within the bounds of the rules as best I can. Sometimes, it's just the mood hits you to be silly and you can't help yourself. Sometimes you're in a bad mood and that ends up showing in posts. I do try to keep that kind of stuff to a minimum though. I believe that's all the mods/admin want from everyone.
All I can say is that I fully support the mods/admin to run the forum as they see fit. If that means they have to get "medieval" on a few members, so be it. I don't know what the ultimate solution is, but I'm confident GBAtemp will survive regardless.