I’m not sure who’s doing this, but
For a detailed overview of the backend "manager" and setting up Users and Groups, please peruse the Content Editor’s Guide.
should read "Administrator’s Guide".
A javascript style switcher is easy. I’m working on a style switcher TV that can be used to switch styles on different templates, since some documents require a specific template, but the look of the site should be consistant. For example, if most pages can be switched from blue, left sidebar and menu, to green, top menu, right sidebar, a specific page requiring a wide, single-column, minimal top menu layout should only change its colors to continue matching the rest of the site while retaining the necessary layout. This could be done with a php switcher, cookies (and/or a field in the web user database table and session), and a careful css file naming scheme.