Questions about Tap dial switch

No, the switch contains a battery.

Hello, the Hue app should have the latest software update. To set it up, press and hold the button with a dot or the first button of the Tap dail for at...

Unfortunately, it is not possible to change the colour only the brightness

Switching is possible, I have also configured it this way. And a long press is then off again, in my case, for example. What doesn't work, however, is...

Yes, that is possible

Yes, each button can be programmed to control a light individually, including colour cycling. The knob can be used to switch all the lights on or off.

Correct
Pressing button 1 switches the stored lamps on and you can dim them.
Pressing and holding button 1 switches...