I switch between playing on my iPhone and iPad several times a day without problems! As long as the devices are logged in to the same gamecenter-account and the game is connected to my iCloud it should go automaticly.
Throwback boxes are the best thing ever! I wish we were guaranteed an "excluse" item when opening weekend boxes also. My last two boxes (yes, I have self-control issues) couldn't have been better!! Yay! All things pink and sparkling shall be mine!