I do not think that karma is a good policy for forums as people can dislike your posts even at the moments they just disagree with your point of view and, as a result, you lack many additional capabilities.
Please note that negative karma should
NOT be given if another user dislikes your post. As explained in my
previous post, negative karma is given to users who
break the rules, and should not be given for any other reason. If you have been given negative karma and you have not done this, then there is a forum court to appeal this.
Instead of worrying about receiving negative karma, a more productive use of time is to try and gain positive karma by making useful contributions to the forum, as many members do here. Then if you have positive karma, you will have less to worry about. It's really not that difficult, about 10x easier than gaining merit elsewhere at least.
PS - This comes from someone who started here with -2K and had to earn their +K, so take it or leave it.