Hi Tim,
Thank you for your reply and for forwarding my suggestion. I would say the example you give would be an excellent occasion to issue a warning. If a plugin developer changes something in a plugin file and WF issues a warning that makes sense. I then can compare the files (great function!) and judge for myself if this is a threat or not. I think this wouldn't conflict with my suggestion that WF should - if possible - compare the installed plugin files with the plugin files of the same version in the repository even when the installed version is outdated. However, that would require older versions to be available in the repository. I don't know if they are.
Erik
WP Webbouw