Mike, I am not sure that those things are particularly valid. There would be some security, fingerprint, facial recognition, password etc, or a combination of factors like we get with 2 stage security on many bank accounts these days, even my google account demands 2 step log in now I notice, so apart from name, age and address, I would think there would be little else on the face of the card. Once you had signed in any information should be sectorial, i.e. medical and relevant data would only be open to access to clinicians etc. As far as losing it is concerned, like credit cards there would be a number to ring to disable the data on the card and a new one issued on presentation of evidence of identity (passport etc). I am not against the idea, but given the people government seems to trust to deliver such projects, it simply wont work.
I would be in favour of a structured approach with initially say a card for every British citizen who wanted one; credit card size like a bus pass, with simply basic info, say just name on the front and then on presentation at a card reader, your basic identity details like address and telephone number, age and a picture could be seen by those who you authorise through the 2 step security protocol. The cards could come complete with plenty of memory these days or could connect to a database where your information could be kept, controlled by you. Then, as the system were proven, more could be added at the individuals choice. I would not be in favour of adding credit cards & bank details or any other things that are adequately covered already, but I would put my bus pass and driving license on there.
All a matter of taste I guess. Whether or not it should be extended to other classes of citizen is another matter.
Mike.X