Prevent Purchases and/or Remove Contact List?

[Jeff29]

I have seen questions here:
1.  How can I protect and prevent purchases for a weekend of family/friends?
2.  How can I remove my contacts from a device I've set up

I think I may have seen an answer and to give credit:

http://www.echotalk.org/index.php?action=post;quote=12222;topic=2214.0

I just found how to deregister:
Deregister a Device

You can deregister a device from your Amazon account if you no longer want to use it to purchase apps or in-app items.
To deregister a device:

    From the Amazon website, go to Your Apps and Devices.
    Click Your devices.
    Click the Actions button, and then click Deregister device. Deregistering your device prohibits Appstore purchases on that device, and disables the use of any app purchased from Amazon Appstore for Android and downloaded to that device. You can re-enable purchasing from the device by signing in to the Amazon Appstore for Android again.

This seems like it would cover both questions.

Additionally, someone may ask if re-registering the device would mean contacts were auto-magically saved and be re-included.  This may still require contacting Amazon support.  I won't be testing it as I won't be allowing access to my contacts until there are better answers to control (like allowing me to selectively add and remove contacts from the list).