I actually had the same problem and had to buy a universal power supply unit. The important thing is the correct voltage and a suitable plug. It worked, but I don't have the data to hand at the moment.
The monitor has no integrated speakers, but you can plug in headphones at the back of the base and play back sound - just select the output device (monitor) under Sound in the Windows Control Panel beforehand!
Sure you can. Connect your laptop, press Win+P, select expanded or duplicate and voilà (assuming you have Windows). It's possible with any screen because it simply accepts the image signal via HDMI and plays it back.