Answer:
Question 1: Extremist is a better term for describing the ideology of a terrorist because they will do whatever they have to do to get their point across. They are willing to go to extreme measures to make a point.
Question 2: Religious fundamentalism been used by extremists in the Middle East to justify acts of violence and terrorism. Extremists groups have used a distorted interpretation of Islamic teachings to justify their violent actions. Anyone who disagrees with them is an enemy and they believe that Western culture and values are a threat to their way of life and they seek to destroy it through acts of terrorism.