Naming of media image files are not theme related. The need for renaming like that after editing or changing a media file it to avoid overwriting the original versions of you uploaded images. Themes and plugins that properly interface to the media library will be able to find the correct name of the latest version of an image. Weaver’s Show Sliders plugin was recently updated to handle this new feature of WordPress properly.
The other thing you asked about has nothing to do with the media files, but is an important and essential part of how Weaver interacts with the TinyMCE Page/Post editor. The methods used for this area perfectly safe and within all WordPress programming standards. Apparently your firewall is overly aggressive in what it blocks.