Otherwise, the clock is very simple. I don't need a lot of bells and whistles. Battery lasts over 7 days. Depending on the application...

As far as I know, you can read various messages as well as WhatsApp. As far as I know, you can read various messages as well as WhatsApp, but not reply via the watch. This is always done via mobile phone.

I can't answer that. I have not tried it out yet.