So I can get a verizon 5s on contract, but it'll work on att and tmobile right? Even while i'm still on verizon service? So i can get the 5s on verizon then cancel service, pay the etf, and switch to att/tmobile? Do i have to wait to cancel service with verizon before putting att on? Does the etf need to be paid off immediately before switching service? Do I have to wait 14 days to cancel with verizon, or is it 30 days?