many files would be left behind with this method
not nearly as many as a PC, and the registry is another matter altogether.
99% of an applications resources are held in the Application file itself in the
resource fork (btw: Mac apps all have TWO eofs; one for the data (code)
and the other for the resources). The major 'other file(s)' would be the
/System/Preferences, and as you say, they just get orphaned. As they are
easily identified by name, they too can be trash, but it does take manual
intervention by the user. 'Hey; any body seen a silver bullet lying about'?