The Forum Access offers huge flexibility for forum administrators. By default administrative control on a forum is done with Access Control settings. One would create a role (e.g. moderator), assign people this role, and in Access Control give that role the rights to edit or delete forum nodes. Forum Access gives the ability to make these sorts of decisions per forum.
For each forum the administrator selects which roles can read, post, edit and delete in that forum. Additionally you can declare specific users to be moderators in an individual forum regardless of their roles. For example an Official Announcements forum is common, and the ability to "post" is limited administrators. Forum Access makes this trivial by, only for the Official Announcements forum, specify that only administrator role(s) can post. Similarly it's possible to create a private forum by limiting the roles which can read postings.
Pager at top and bottom of comments helps with a usability issue which arises with forums. Forums tend to create long chains of comments, and by default the "pager" only appears at the bottom of the page, making it that users must scroll the page all the way to the bottom to find the pager. The pager is the links to the subsequent pages which arise when there are more comments than will fit on a page. The linked code snippet is a theme tweak to make the pager appear at the top of the page as well as the bottom.