Yes, you are misunderstanding how backbone is set up for the boiler plate for this game engine. Interfaces are basically 'read-only'. Read the wiki on the craft boiler plate. If you want to create new interactive crafty entities you need to create new entities , not interfaces.
So, for example, you would go to your scene file and declare a new entity:
sc['info'] = new Info();
You also want to make sure the AMD is calling your new entity file. Then basically that file you have ther could be moved to the entity folder and you should get your interactivity.