DP cable with 4K & 144hz is included, HDMI is not. Nothing lights up in the back of mine.

The leds are switched off by default and can be switched on in the core lighting menu. The lower jaws also have leds, but they can be switched off separately. The rear leds are rather weak and hardly visible in normal room lighting. In addition, when the monitor is mounted on a monitor arm, most of the light is blocked.