If a story is rated 8, but then goes back to 7, they keep their honors because they managed to make something good enough to be an 8 for a week, the same way everyone who's been in my 4th grade class hates Island of the Blue Dolphins, but it still has a newberry honor.
They can still see the ratings, the rating itself just depends on the reward or penalties. Unless the only conceivable way to script this is not to display the current average, that is.
Yeah, the trolls will always be problems, and they are often addressed sooner than later, but notice how ratings reset once a person has un-published and then re-published a story. While the point ordeal would be a problem, a person must simply contact the nearest moderator and point out any injustices, as with all troll problems. There could also be a waiting period for points as well, which might help root out cheating duelists too, but that would be a SHIT TON of work, much less so if we held community votes among the populace, though. But that could easily go wrong without a lot of applied thought.
And yes, the point penalties displayed represent the total point loss, regardless of the initial reward.