To rename a file, Thunar has a very inconvenient small box where one cannot see the whole file name.  It should automatically size itself to display the whole file name one is trying to edit.

This is one of the little inconvenient features that makes me run Nautilus whenever I can, even though I would like to get rid of all the Gnome applications.  It is a hassle when file names are regularly 25 or 30 characters.