A:AnswerThis device came with a dead battery and one that was not chargeable. We had to return the phone due to this problem. It was such a headache that I will not buy another used iphone.
A:AnswerYou don’t *have* to have the carrier and you can go off of just WiFi but it limits you to what you can do.
Without a carrier you can not text or call.
Without a carrier you can not be on the internet at all unless you are connected to WiFi somewhere which limits you.
You’re better off getting the carrier so you can do what you want when you want wherever you are.