The first general option indicates whether Glade should generate code to support the GNU gettext library so as to support internationalisation. It is a good idea to leave this on (which is the default). Internationalising your application is an important step in making your application user friendly.
The Set Widget Names check button is used to tell Glade to generate code to set the names of all widgets in your interface. This is relevant if you find that you want to use the Gtk+ function gtk_widget_path().
The Backup Source Files check button will cause Glade to copy files to .bak backup files before overwriting them. This applies to the .glade file and also to the source code files.