I already know you have never read the Quran, but I agree with you about some of it. The Quran like the Bible, has many different directions (as it wasnt really written by one person). Some are peaceful and some are violent. The Old Testament is a very violent book. Jews arent. These books are structured in a way, with so many different ideas, that you can take the ones that mean good to you. However, the Quran can be used to justify violence, and ISIS are NOT fake Muslims. They are radical, but there views are perfectly legitimate interpretations of the Quran. Now on this we could fight with Quran quotes, but they are peaceful quotes and violent ones. A perfectly accurate interpretation of the old testament is to go to war, plundering cities, and raping the little girls. The Lord is a man of war after all. But Jews dont do that. Muslims do these days. Of course, they are radicals, but note that a high amount of Muslims do support terrorism, and it is hardly condemned by the establishment. Without a doubt Islam is the most violent religion today, but it isn't inherently violent. No major religion is. The New Testament is very peaceful(relatively), but in times of history Christianity has been the most violent.
My point is that right now a good amount of Muslims support violent Islam, and a majority support Sharia law, but that is a problem of Muslim ideals today, not the religion itself. Islam is not a religion of war.