You're missing the point completely. The Second World War had nothing to do with religion, obviously. But it did have to do with a lot of complicated socio-economic and political issues, and not just "it would have happened for another reason anyway," which is a really lazy argument. Contrary to what you think, things have real life causes that can't just be substituted for one another.
As for your friends who try to "fully understand the transcripts", don't you think suicide bombers genuinely tried to fully understand the transcripts, and arrived at something different than your friends? Furthermore, I can guarantee you that your friends have wildly different takes on scripture than the original Christians from the first centuries CE. One would think the early Christians would have a better idea due to how much closer they were to Jesus in time.
In response to your first paragraph, you have pretty much proved what I was trying to say. Yes saying it "would have happened for another reason anyway" is lazy and I apologize for that but what I am trying to get across here is that there are many other reasons for war and conflict other than religion. If religion never existed and the common reason for most wars was due to politics, would people demand to get rid of government and politics as it's the reason for the majority of world conflict? Probably not. I don't think Religion is the problem but rather the people who use religion to rationalize whatever extremist view they have.
For the second paragraph, please do not assume I am Christian or the friends I was referring to here are Christians. I am an Islam revert. Suicide bombers are in most cases people that have been brainwashed by someone who uses passages out of context for his own agenda. From when I was taught the Quran, my teacher persistently referred to the quote that roughly translates to "If you kill one innocent human being, except in self-defence, then it is like you have killed all of humanity and you will forever burn in hell". For me, that advocates peace rather than terrorism but an extremist can easily look at this and think "those fecking Americans hate us let's kill them in self-defence". Now by looking at this, is the problem what is written in the Quran or is the problem with the person that interpreted it?
The Qur'an repeatedly states that defensive war (fighting to protect yourself against invading enemies) is the only kind of combat sanctioned (2:190 - 191). In various other examples, it teaches that the use of force should be a final resort (2:192, 4:90); that normal relations between people, nations and states, whether Muslim or not, should be peaceful (49:13); that necessary wars must be limited in time and space (2:190); that utmost effort must be applied at all times to advance the cause of peace (10:25); that whatever means are undertaken to work for peace during a conflict (such as mediation and arbitration) must be attempted over and over again until resolution is achieved (8:61); that freedom of religion must be granted to every one (2:256), and so on.
There is a lot of peace in religion but these things are ignored. A lot of people say that the Quran teaches it's followers to preach with the sword but the word "sword" isn't even in the Quran.
As for the bolded part, again you are are being presumptuous. Me and the friends I was talking about follow the teachings of prophet Muhammad and the first three generation of followers, as to stay close to his teachings, because in time, many things have been altered through culture.
I'm not squirming, I'm right here. 
Thank you, mods!