A:AnswerYes you can, you can either stream music over WiFi or “sync music (which is downloading it onto the watch). Because this watch does not have cellular, you unfortunately cannot stream music unless you ahve your phone nearby. You can also connect a Bluetooth pair of headphones to the watch!
A:AnswerI charge mine every night - could probably get away with charging it every other night but that would be the longest you could go without charging.
A:Answeryes for the gps you need your phone close to you, for the gps+cellular you can leave your phone at home and still get everything on your watch. the only way that your watch works with texts and calls is if they're connected via bluetooth. your phone can now connect to more than one device, I have connected my bluetooth to my braven speaker and watch still does everything with no interruption.