A:AnswerIf it is unlocked, yes.
You would need to get local service in the country you are going to or a data plan on an either locked or unlocked phone with your service provider.
I can’t say but I imagine you can purchase an extended warranty from Best Buy.
A:AnswerWhen you buy a phone from Best Buy, you open a credit card account that pays for the phone. You just pay to the credit card the monthly bill. You can keep virgin mobile if the phone is unlocked