Admittedly, I didn't read any of the links. I am not denying that there are plenty cases of people performing acts of violence and terrorism in the name of Christianity. However, they can almost always be discounted as nutcases or brainwashed because Jesus does not advocate violence. Some Christian groups have gone to the opposite end of the spectrum and have refused to even defend themselves should they be attacked.
Whereas Islam promotes the spread of their faith through violence and terror if people don't willingly convert. You are very educated on the topic and can probably speak more accurately about it though.
FTR, Anti-Balaka groups in the CAR are responsible for massacres and displacement of thousands of Muslims and have been reported to take part in forcibly converting larger numbers of muslims under threats of violence. That's more than just a case of a lone fanatic like Eric Rudolph.
You're right, though: Jesus did not advocate violence. But there are parts of the bible which can be interpreted as condoning or advocating violence, and that's all some fundamentalists need. Until Jesus showed up, the bible was full of violence and genocide. There's a reason the phrase "going old testament on someone's a**" exists. Sure, there's the whole new law vs. old law thing that supposedly does away with all that. However, it's still all there for people to interpret/misinterpret as they please.
People like Timothy McVeigh may be seen by the majority of Christians as acting outside of the teachings of Jesus, but it doesn't change the fact that they drew inspiration for their actions from a fundamentalist interpretation of the same book that Quakers read. It's not any different from fringe groups of any other religion.
The main reason Islamic and Christian radicalism differ so much though is that Mohammed's movement was always a political and religious movement meant while Jesus' movement was inherently apolitical. So even though both books have plenty of fodder for people to (potentially) use as justification for acts of extremism, it's a lot harder for Christians to justify acts of terror made for political change than for Muslims to do so.
While I don't personally agree with the argument as a whole, those who try to call Islam "a religion of peace" do have some points they can make in their favor. Islam throughout it's history has been closely tied to violence. However, it has had it's spans of peacefulness and tolerance as well. Islam hasn't always been so antagonistic towards Judaism and Christianity. There were times (usually when Islamic empires were wealthy and somewhat content with their place in the world) that Jews and Christians living under Islamic rule were protected from violence as "people of the book" (basically the Islamic way of recognizing they were all 3 Abrahamic faiths who worshipped the same god) and faced little persecution outside of having to pay higher taxes. There were times it would have been better to be a Jew living in the middle east than in large parts of Europe. Or to be a protestant living in the Middle East than in a Catholic country (or the other way around).
The Islamic golden age was perhaps the most stable the middle east has ever been. Without Islamic scholars who translated and studied a great number of hellenistic and ancient greek texts, we may have lost some great works of Ancient greek literature, philosophy, and math forever.
But still, that's all hundreds of years in the past and doesn't change the fact that the only times we've seen tolerance and peace out of Islam was when there was a large, powerful empire leading the majority of the Muslim world who just so happened to have greater self interest in maintaining order than in converting the entire world to Islam.
