Dear Gina Lee,
Social life for expats in Ethiopia is not difficult, especially with the expat community. Most of the expatriates hangout in some specific places in Addis Ababa and joining them is not difficult. Internet connectivity in Ethiopia is one of the slowest in the world. However, wireless internet services have been launched since recently and it is getting better with the wireless services which, for personal use, on average may cost you from Birr 500 (USD 35) to Birr 1,000 (USD 71) per month.
Regarding travelling to other African Countries, there is no problem as the Ethiopian Airlines, one of the best in Africa, travels to many African countries than any other airline.