There is no Ethernet port on Espresso. You need to get a USB Ethernet adapter to connect to the network. You can use an external modem to connect to the Internet. You can use the serial port modem or USB modem. Or you can connect to the Internet through the Ethernet adapter with a cable modem.
All extensions are via USB port.
All the key components are upgradeable. If you do not have a VGA monitor, you can use TV set as monitor to operate your system. I find there are one VGA port and one Video port on Espresso. Under Windows 2000, you can output both VGA and Video at the same time. There is an orange part in the topside.