While I understand it's not just a matter of migrating a database; given I strongly suspect the current forum software used here is probably EOL and/or not the latest version of it, I'd think an upgrade of the forum software would be a far better idea. As more recent forum software will likely have stronger protections and filters in place already, rather than continuing to patch an outdated mess.
Also, I think that there are some members here (who would be banned for good at other forums, if they posted the same abuse there that they post here) that should have a ban imposed on them. As at the end of the day, if some are going to abuse others no matter what when others are simply disagreeing with them, then they are obviously not capable of being civilized. In that case the only real answer is to remove them from the forum altogether, if they are unable to control themselves. And it doesn't
mean everyone has to always agree with each other, or be perfect either.
All of that said, in regards to the voting system; the last forum I participated in, being a Linux forum, did have a "reputation system" where you could not actually give negative
reputation (although vBulletin does have an option to enable that though), you could only give positive
reputation or not give any reputation to a post(s) at all. But it didn't stop people from abusing the system though, for example, if the main developer of a certain Linux distro just posted what they had for lunch, they would get a ton of reputation even though it didn't help anyone with any technical problem, let alone answered any technical questions - but they still had/have more reputation than posts made by them. So the simple fact is that if humans use it, someone will abuse it, that's life. The only way to totally prevent any abuse would be to adopt tsarstepan's suggestion, and get rid of the voting system here altogether. But again, it would be smarter to upgrade the forum software, regardless of whether or not the admins here adopt that suggestion or not.
And yes, I did up vote tsarstepan's post for the record...