There's an existing setting about displaying the shortname, courselistshortnames 'Display extended course names'. This changes the behaviour of the API function get_course_display_name_for_list.
IMO, if there is anywhere in Moodle that displays a list of courses that only displays the fullname and not the shortname, then it should be using this API function/setting.
I haven't checked, but I actually thought that some of the places you listed already took note of this function. This code, or some of it, may be in 2.3 rather than 2.2 though.
Anyhow - if you've got that setting turned on, but there's a place which lists multiple courses and doesn't show the shortname, then you could probably submit a change to that effect (i.e. just make it call that function instead of where it currently does $course->fullname), and I think it should probably be accepted?
--sam