Wow, I go to sleep for a few hours and I lose control of the thread xD That's ok though, love the discussion.
Friendly: Islam is indirectly the source of the terrorism. The true source is people like bin Hidin', Ayman al-Zawahiri, and all the Imams and Clerics who preach militant, radical Islam. Their words are supported directly by the words of Muhammed in the Quran, and that handily explains why all these terrorists are so hardcore for Islam, believing that they're fighting Allah's fights for him and guaranteed paradise in his service.
There's not much difference, in religious mechanics, between Christianity and Islam. The difference is in the books. Biblical violence is directed at Ancient People A, Quran violence is directed at Unbelievers- who exist today. I daresay you're likely one of them.
Muhammed's words aren't the causation of violence. They're the support of it. The religious leaders who recruit the misguided youths into terrorism are also the ones who justify terrorism in their minds, even though the Quran states, in some places, that enemy combatants should be the target. In the other places its not so clear, and one unbeliever dies like any other, combatant or not.
If Islam didn't exist and all Muslims were Athiests (notice I'm speaking worldwide here, not just the Middle East- terror is happening all over the world), terrorism would still exist as a means of the weak to fight the strong. It always has existed in the form of guerilla warfare, and only recently has it become the widespread epidemic of suicide bombers that plagues the world. Without Islam, the weak would still be fighting against the strong -and- attempting to keep themselves alive to fight another day. So, yes, Islam is the indirect cause of terrorism as we know it. If Islam didn't exist, terrorism would still be happening, but in a less horrific manifestation.
You want less gray areas in life? Yes, it can be bad. Yes, it can be good. Yes, bad and good in this world can be hard to define. Thats the way the world works. If you want a more black and white definition, you have to skew your vision so that you can only see one aspect of the world- one way in which it can be good, one way in which it can be bad.