Not “Islamist terrorists” but ordinary devoted Muslims. This is what their religion teaches and what they have always done when they have the chance. They are only following in the footsteps of Muhammad, the Perfect Man™. So by all means, let us have more of them move into the West.
Egyptian President Sisi does not subscribe to what you said.
Look at his actions. They have been consistent.
However, the germ of these abuses are in the Quran.