I've a few suggestions more.

IP adresses matching the same IP adress as the uploaders should not being able to rate the upload, the same account should not being able to rate its own upload

A report option in bottom of reviews so you can repport unfair reviews instead of bother with a PM

Ability to ingore PMs from non-moderating users

Must have e-mail for sign up, and only one account per email (only for new accounts in v2)

Remove the rating ability from links, and give ability to the athour of the link to delete it (It's a link, it shouldn't be reviewed, only commented)