I added pay per use international long distance to my plan and wish to confirm this add-on Intl' long distance add-on covers me to call from the U.S. to Canada when I travel?
No it doesnt. The description for the Long Distance Saver add on is:
"Gives you access to discounted international long distance rates for calls made from within Canada".
Actually it is only necessary when calling from outside the US and Canada. All it does is provision you phone to connect to the networks of carriers in other countries. You will pay for calls at pay-per-use prices (about $1.50 / minute in most locations) See the "Don't Want to use Easy Roam" section of this page for more info.