Excellent piece pulling together theories, making them understandable and relating them to current practice and people. Possibly only missing Lave's concept of peripheral participation and community of practice. I have always assumed an affinity between the idea of a journey from periphery to centre of a community of practice and that journey across a ZPD
when you interact with a service online or by phone there may be software in action that mediates how you experience the service: by sorting you. Live in a high income postcode? Get routed to a sales person more quickly than if your IP address makes you look as if you come from a less promising area. On record as an awkward customer or "time-waster"? Then wait in the queue.