Yes, religions do change. Often for the better. I think the bigger question is: "Does Islam want to change?"
Until then, regardless of how large or small it's terrorist arm is considered to be, it is a dead issue. And any change will require dropping their terrorist arms and require more pressure from their enablers, like our own lefties and the French leadership.
That's too simplistic. That's like saying until no one who identifies themselves as a Christian opposed abortion then all Christians are heathen.
Islam is spread over many diverse nations, sects and societies just like Christianity is. And just like Christianity, there are the devout and those who pay lip service, just like Catholics who vote for pro-abortion candidates.
Religions used to change societies but today it's more often the reverse, societies change religion (religion adapts to society to perserve itself...again, the Catholic Church in America is a good example).