Hi @Stefan_fr, thanks for contacting us. The webflow.js and other .js file is required for proper site operation. There are many different settings and functions in that file and it is not recommended to edit those. The file is provided with the export and can be uploaded to your server. You should not have to edit these files, just include them, as they are linked to your pages on export and there will be scripting errors in the console if you remove those.
I hope this helps, if not, let me know and I am happy to assist further