hmm, my post got lost, anyway, I was just saying that you can definitely do that.
You will want to provide a 'insert_xxx_object' method that knows how your object has to be broken up and issues all the create->()->create_related() calls to write them to the database. This one would go into a ResulSet class for your 'main' table (or any one of the tables that are involved in storing this object), which you may have to create first.