I'd read the docs carefully. They discuss the Student-Course issue.
I'm not entirely sure you can just create a whole DB like you suggest though, but maybe you can. It might be better to build a db properly outside of Marketo and then use the API to populate the data. This might work best in SFDC given how you can pull those custom objects in.
Thanks for your response.
Apparently this may not work - we will go with a different approach to 'fit into' Marketo way.