I tried the Internet Explorer Settings preconfigured backup. While I expected it to just backup my bookmarks, it seems to be backing up a whole lot more?

The IE Settings backup is configured to backup all related to IE - history, temp files, security settings, etc - so if you need to restore, you get your IE exactly as it was earlier. If you wish to only backup the bookmarks file, you simply need to configure this as any other file backup after manually selecting the file.