Progress! I've created an EntityLoader class which can load entity definitions from a file with LoadFile(), and return a ready-made Entity to calling code with ConstructEntity(). To try it out, I hand-wrote a Player entity definition into a file and had EntityLoader load it, then I passed the result of loader.ConstructEntity("Player") to the entity map's AddEntity method. Works great! ^_^

EDIT: Class layout updated. Also, I added a link to it at the top of the journal, by the color-coded project name.