A:AnswerNo, you don't need to be connected the DP cable to use the camera and speaker. Yo can connect it with VGA, and there is an USB cable which needs to be connected to your computer to use camera and build-in speaker.
A:AnswerYes, this monitor should work with Apple computers, you can connect the monitor via the DP port. However, the webcam drivers are available only for Windows platform on the Dell's support website: https://dell.to/3hNBDCB