Egyptian
Standard american english
The most widely understood English dialect
Body posture
Officially Modern Standard Arabic is the language, however, most people speak Darija Arabic, also called Tunisian Arabic.
The dominant language spoken in Egypt is Arabic. Specifically, Egyptian Arabic is the most widely used dialect in everyday communication.
The main language spoken in Jerusalem is Hebrew. In addition, Arabic is spoken by the Arab minority there, and English is the most widely spoken foreign language. Street signs are in Hebrew and Arabic (and sometimes English as well).
The Najdi dialect of the Arabic language is mainly spoken in the Najd region of Saudi Arabia, which includes the capital city of Riyadh. It is considered one of the major dialects of the Arabic language and is widely used in central Saudi Arabia.
It depends on what you plan to do with it. Obviously, if you plan to work in a certain Arab country, knowing that dialect will be most useful. For example, you may be going to Iraq for military purposes, so it would be good to know Iraqi Arabic, etc. If you want to be able to watch television and movies, Egyptian is probably the best dialect to learn since most Arabic language television (except for news stations) is made in Egypt. However, the drawback to learning Egyptian is that it is rather different from other dialects, resulting in Non-Egyptians understanding you (because of these TV shows), but you not understanding Non-Egyptians. If you want to learn other dialects more easily, Levantine dialects (Palestinian, Jordanian, Lebanese, Syrian) are probably the most useful since they are more linguistically similar to other dialects.
Arabic -- although each country speaks a different dialect.
"Arabic" usually refers to the Modern Standard Arabic dialect, but the actual spoken dialectal Arabic used by regular people varies almost as much as different European languages. Egyptian Arabic is the most popular dialect because of their television industry and popular culture. One common difference from other dialects, is that Egyptian uses a hard "G" like in "great", while most others use a soft one, like in "age". "Eastern Arabic" most likely refers to the dialects used on the Arabian peninsula, and could be Gulf Arabic, Iraqi Arabic and/or Levantine Arabic.
Eastern Arabic is also referred to as Syrian Arabic. This dialect is most usefull in countries like Syria, Lebanon, Jordon, and Palestine. Other regions like Saudi Arabia, Iraq, etc., use different dialect, but can usually understand both Syrian and Egyptian dialects as well.
NO. While there may be individual Egyptians who speak Italian, this would constitute less than 1% of the Egyptian population. The predominant spoken language is Egypt is the standard Egyptian dialect of Arabic, followed by the Saidi and Badawi dialects of Arabic. Proper Arabic or Fusha (الفصحى) is the most common written language. English is the most commonly spoken and understood foreign language.