As long as you get much more +karma than -karma and you get -karma just occasionally (if all your posts are good), it's not the real problem, and karma system works good. Of course it is unpleasant to get -karma, I get some rarely and I don't like it also, but I get more +karma, so it is not a real problem to get rarely -karma.
Yes, that's true when someone gets more +karma than -karma then that user should not worry a lot about it, but of course the online world is improving so I taught that why not this forum? I mean YouTube totally disabled dislike function from videos and now no one sees any dislikes on a video.
If I'm not wrong then I consider karma more as like and dislike thing instead of merit thing that we have on Bitcointalk. The good thing about Karma is that all members can send unlimited Karma without any restriction, but they'll have to wait 10 hours if they send a karma to someone, however during that 10 hours they can send more karma to other users.
Do you like when all the topic if full of answers to the opening post or when there are some insults, etc?
No, I personally don't like to see all posts of a topic as replies to the original topic because there won't be any conversations and arguments, plus sharing of opinions with those who make posts on that topic.
I really don't want to see the insults but if I'm not wrong then freedom of speech should be there and user don't get scared when they don't like something. Because if someone makes argument with a user even if his stance is correct, the counter party will give him a negative karma for that. Which to me isn't a justifiable thing, and such kind of -karma behavior should be stopped that's what I want.