Some of the issues you raise regarding rating editors could be mitigated. If each user is allowed to rate any other user only once, it would be more difficult to improve or discredit other users, without creating many accounts. An editor would not receive a rating until they have x number of ratings from unique users. The scoring could be dropped completely, and only allow the ability to indicate if you believe someone is a good editor. The only way to give someone a negative is not to rate the person, or withdraw your rating, if that was an option.
I can see where building a catalogue of rated sources could be a challenge, but I think it is worth exploring.