Plug the Multiscreen into the screen via the HDMI-connector. Connect the USB-cable to the Multiscreen and to a power supply (e.g. USB-connector of a TV set or USB adapter)
To connect a smartphone or a tablet PC to the Multiscreen please go to Settings > Display > Wireless display
Yes, this is normal. The aluminum housing has been used to improve the work and lifetime of the device. It acts as a radiator and dissipates heat into the environment.
The normal working distance is up to 10 m. It depends on obstacles and the transmitting device specifications.
Audio and video files are not transmitted to the screen directly. A smartphone or a tablet PC transmits the signal packages in H.264 codec. This means that all transmitter device formats can be displayed via the Multiscreen.
The Multiscreen can be connected to any screen with the HDMI-connector, for example to a TV set, multimedia projector or monitor.