changing the labels inside appearance -> menus for some for the fields

I don’t have the time to work out a complete solution (which could be pretty complex) but, if I am reading things right, by default WordPress uses Walker_Nav_Menu_Edit to create those backend menus. It looks to me like you can build your own walker for the backend and pass it in via the wp_edit_nav_menu_walker hook.

If you did that, you should be able to not only rename those fields but add your own fields to keep things neat.