Petr "the switch role will never be 100% accurate"
Very true. As far as I know of Moodle, the switch roles feature is there to enable a teacher to see more or less what the various parts of a Moodle course will look like to a student. The "more or less" aspect varies amongst activities and modules, sometimes it is 100% and for other activities it is near impossible to completely mimick the student role.
The only way to really test moodle as a student is to log in as a real (or dummy) student.
We can only hope that the switch roles feature of Moodle 2.x will be nearer that 100% for most activities than previous versions.
Just found another example.
When logged in as Admin, Switch role to Teacher, the Settings block still displays the Site Administration menu, which is normally not displayed for the Teacher role.