When authorizing all of our Joomla sites with Dropbox, there seems to be one single entry for Akeeba in the Dropbox Security settings where all authorized apps are listed. There isn't one entry for each of the many websites we have hooked up to Dropbox using Akeeba. So there does not appear to be a way to disable access by one website to Dropbox. This is a problem in one case where we no longer control a website that is still connecting to our Dropbox.
Jordan