I feel the pain. I have trolls on my Youtube videos who sign up for notifications just to give me a thumbsdown. I could make a video with puppies who cure cancer and the troll would still give it a thumbsdown. I guess those people are universal and are the crabs in the bucket.
The good news there are a lot more people who are positive and supportive then trolls.
I really like your ideas, I would also like to add that you can vote someones negative comments away. So if a troll gets on to do nothing but leave hate filled messages Steem will just make all their stuff invisible.