I'm still baffled by this "Permission to create surveys (for which all permissions are automatically given) and view, update and delete surveys from other users"

All my users ("survey administrators" in LS-speak) are in individual projects: they MUST NOT be able to interfere with each others surveys (ideally they shouldn't even be able to see they exist). If I give them Create permission (which they presumably need, otherwise they won't be able to create any surveys at all), this appears to let them do anything they want with other users' surveys too.

Is it possible to set permissions such that no user can access any other users' surveys?

If you give the user global permissions to create and export surveys ONLY, they will only be able to see their own surveys.