I'd like to comment on the whole author response thing.
I think it is almost perfectly fine the way it is if you really sit down and analyze it. The people that leave those kind of responses are spammers more times than not and responses like that only make people not want to review or watch the submission.
If it's an honest author and he leaves an abusive response then it will just turn people away from reviewing his submissions and he/she is only hurting themselves.
The author should always have the last word. When a reviewer comes along and leaves a completely ignorant review the author should be able to call him out on it. That's my personal opinion though.
Also, authors need the ability to edit their responses when they change their submission or something like that. Since there is an edit response button that would make it all the harder to code and moderate. If they don't have something that tells them when someone edits their response then the author could leave an abusive response, have people mark it, and then change it. If mods could see the edited responses then it just seems like more work than is needed when you could just ignore the response all together, because it doesn't really change anything anyway.
That's my opinion. I just think it's easier and better to ignore.