You can change the email address on your Account when you are logged in. However, please know that you can not change the Account Nickname. You can use either the email or the nickname as the username to log in.
If you want to Unsubscribe, you can do so by scrolling all the way down to the bottom of the last email you received and clicking the "Unsubscribe" link. Or just click here.
This only affects news article updates and marketing emails with new products, etc. You will still be able to place orders, and you will still receive your confirmation email and shipping notification email when you place an order.