Create a custom role that enables only Comment Moderation actions and pages.
It is a pain when WordPress needs the 'edit_posts' role when you JUST need the Comments SubPanel. Which makes it hard if you want to assign somebody as a simple Comments Moderator.
This plugin will create a special user role called "Comments Moderator" that you can use to create any user account with. They will have access to the Comments SubPanel and all its functions, but nothing else :)