Yeah, we won't be able to save the system from abusive users who do things on purpose, the idea of my system would be to make people think about the rewards they give. Like I mentioned to another user, if we can reach 10% of the users with that, that'd be a huge success already.

About the usability, I agree that we have to make it as easy to use as possible for new users. It wouldn't be much of a problem to hide this bar for users with less than x VP and enable it with a explanation as soon as they reach it.