Yes. This plugin allows the use of revisions and will add entries to the database in the posts table. The database is accessed using WordPress and PHP core functions and there are no direct SQL queries.
Yes. This plugin will save and delete files to the filesystem. The files will be located in the uploads folder under the sub-folder "global-js" on a default WordPress installation.
Yes. The plugin works in a multisite environment as it creates files and folders in the site's own portion of the uploads directory.