1 I don't use Whatsapp so I can't answer.

2 There is no delete option. I guess they delete on their own after a while.

3 Some watch faces have battery indicators that show the charge level. I think it only takes a little over an hour to fully charge the watch.

4 To get the screen to come back on flick your wrist or tap the screen. A safe button to press would be either up or down.

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