Stories are placed into a moderation queue when submitted, then are voted on by registered users. When a story's score (the sum of all positive, negative, and neutral votes) reaches a configurable threshold, the story is either posted or dropped. The exact mechanism and a description of what the thresholds are and how they interact is described in section 4.1.
To short-circuit the problem all Scoop sites have when first started, that of having no users to vote stories up and therefore no stories posted to attract users, the administrator can manually post articles. When enough active users are present, the moderation queue can be opened to members with the thresholds set suitably low and raised as the membership grows. Details can be found in section 4.1.3.
An open moderation queue is one in which all registered users have permission to view and vote on submitted stories. Stories are posted or not depending on what the users choose. For full details on configuring the open queue, see section 4.1.
A closed moderation queue is one in which only editors, but not any registered users, have permission to view and vote on submitted stories. In a closed queue, the editors will also generally have permission to edit the stories, so the queue then becomes a place for the site's editorial staff to prepare stories for publication.
There's no way to edit a comment's text. As an admin, all you can do is delete it, which is irreversible, or change it between editorial or topical, which is easily reversible by simply changing it again. For more details on what is possible with comments, see section 4.6.1.