Found an article that offers a better idea of how it works. Doesn't address all the questions but it is a start. Hope to be using them in a few weeks

Per the article, " The passport information and biometric captured is then cross-referenced to verify the passenger is who they claim to be and then checked against government watch lists. The passenger answers immigration questions on the kiosk touch screen and once cleared is given a receipt to show as they exit the customs hall. Passengers do not need to interact with an immigration official unless there is an error or concern."

http://www.aviationpros.com/press_re...rder-clearance