The GUI provides just the Favorites menu and the 'Add Favorites' option. So a simple user cannot remove a favorite from the menu.
(for geeks: open the bookmark.ini with Notepad and delete the desired line)
...I think that when we'll have ready the GUI for the Auto-Correct engine we can use exactly the same model code for another view - the one for Favorites.
We need sometime to update the Favorites right-click menu support to bring it in par to the main Folders tree. IOW - on-disk management primitives (Copy to/Move to etc. - see the Right-Click menu there) as well as drag & drop.