I'm not sure if this is a bug or a feature or it goes to my understanding of roles.
If, as an admin, I use "Switch role to" student from the top of the course I still have Manage Files permissions in the wiki. Example: can upload images.
If, as an admin, I use "Login as" a user with student permissions I cannot manage files.
Is this expected behaviour? Therefore is the only true way to test student permissions to have a dummy account and does this not invalidate the "Switch role to" drop down somewhat?