A:AnswerYou cannot use foreign credit cards online. In a store it can work, this phone is unlocked but has a locked bootloader (if you don't know what that means don't worry about it). Also, Pixels sold in the USA are not the same as there is a separate global model sold worldwide outside the US which has different bands for carriers.
A:AnswerI’m not a Best Buy team member but a frequent phone shopper. The version that Best Buy sells is unlocked and works on Universal GSM network. As for shipping, I don’t think they do business outside the US (base on my opinion).
A:AnswerThey should all carry the Pixel 2 on release day however not all stores will receive it at the same time; still call ahead to your local store and verify that they have received it.