A:AnswerYes you can with the proper attachment. You’ll probably need to purchase an HDMI that will connect to your phone. This monitor has both an aux plug in as well as an hdmi to connect external speakers.
A:AnswerVerify that your monitor speakers are the selected output device for Windows. For more advanced troubleshooting help, please reach out to ASUS Support either by phone, chat, or email. https://www.asus.com/support/
A:AnswerFrom what I know you can use a USB-C to HDMI converter cable, or a USB-C to HDMI docking stations, and use that as secondary display for your macbook.