Connect the USB cable (supplied) to the USB cradle (supplied). Then, attach the Walkman to the USB cradle.
Make sure to connect the terminals ( 1 and 2 ).
Yes, you can connect it with phone and talk and can use as a normal Bluetooth headset.
Hold down the button 1 for 3 seconds.
You will hear the startup sound.
When the Walkman turns on, the lamp (2) lights up.
Yes, Sony NS-WS623 does have NFC connectivity option.
Yes, it does have fast charging. Charge it for just 3 minutes and it will work for another 60 minutes.