A:AnswerThe phone connects through Bluetooth, WiFi, and LTE. It picks the most efficient way. Ie. it won’t use LTE if your phone is right next to you and will use WiFi if you are on the same WiFi.
A:AnswerHi!
Firstly, you would have to get the cellular version of Apple Watch Series 3 or Apple Watch Nike+.
Now, the answer:
Most likely not, as it is not on Apple's official Supported Carriers List. But, you should contact them jus tot be sure, as Metro CPS is owned by T-Mobile, which is supported.
Hope this helps!
:)
A:AnswerYes. No problem. Just make sure you are matching the band size (38 or 42) to the watch size (38 or 42) for the best fit. That said, I know people who put a 38 band on a 42 watch and no one knows the difference. Putting the 42 band on the 38 watch is a bit noticeable.