Is it possible to delete the theme mode so that unnecessary css and js are not loaded?
Is it possible remove not unnecessary js ?
Why burden the site with unnecessary code?
Sure, the unused code can be removed using Metronic's Gulp or webpack builders.
Basically, the theme comes with all features and demos included and you can just remove unused scripts, plugins, and pages from your build.
For more info please check this related post.
If you need any further help please let us know your Metronic version, the build method you use(gulp or webpack), any console error logs, and the features you would like to remove.