Saudi Arabia is likely more worried about Iran because Iran's Shiite Islamism makes Iran an intractable enemy. Saudi Arabia knows that as long as they monetarily support Islamic State that they can push off direct confrontation.
The largest Islamic country by population is Indonesia. The most important country in the Islamic religion, however, is most likely Saudi Arabia, as this is the area where Islam was founded.
If it is an Islamic name, it's not a terribly common one. More than likely, it is not an Islamic name.
If you live in an Islamic country-example: Saudi Arabia or Kuwait or Egypt, etc; then you most likely don't have work beginning from iftar until taraweeh is over. Also, when it is time for you to go and pray.
Westward expansion
The main item traded between Arabia and Europe was most likely salt.
Most likely Saudi Arabia.
Nomads were most likely to interact at the bridges of Arabia
Well Yemen is south of Saudi Arabia and Nepal is south of China. So the answer is most likely China.
Westward expansion (APEX)
No, he was from Saudi Arabia. More likely an Arab.
It is quite likely that agents of the Islamic State are in the United States. However, they have not yet been able to perform an attack on US soil.