The Explorer I Router has Ethernet support for both WAN and LAN operations independent of each other.
The Explorer I Router Ethernet speeds include 10/100/1000 Mbps operations.
No, the Explorer I Router will automatically detect the Ethernet speed, including 10/100/1000 Mbps operations.
Typically, devices that requires extremely high bandwidth use are best suited for a direct Ethernet connection. Smart televisions are an example.
The router uses the standard RJ45 Ethernet connector. CAT5 (or higher) is your best choice for cables. The Ethernet wiring may be either a straight thru standard patch cable or a cross over cable.