a bold question which I would like to expand on:
Has anyone ever set up a site with numerous single course in a way that the LMS is not visible? I have several courses which I am training on behalf of different institutions. My objective would be visibility of one course only for that course's participants with no navigation back to the LMS starting page, preferably not even through manual URL modification.
Test environment: http://www.eamebus.de/moodle/