You can easily remove all access to the web browser and the shop using a script I wrote for the purpose.
If you buy a book (on a computer) it will come into the library on a no shop / no browse modfiied NC.
the web browser and shop themselves are backed up, then deleted from the program area of the device - they can be restored but until they are restored, neither exists and thus the device ought to be harmless.
details at http://nookworks.blogspot.com/2011/07/i-want-to-lock-down-browsing-and.html and confirmed viable within the last month.
Not how I'd configure my device, but if you want that control, there you are.
