Muslims are the only people who claim their book can't be translated

That is true, Arabic is such a complex language to learn that I (spent 4 years learning it) am not even close to being fluent at it. I'll get downvoted for having that opinion, and very few will believe me, but I know I'm right. Once you start studying the Arabic language and reading the Quran you will realize how wrong you got it, and how the media is brain washing you into thinking something that is completely untrue. I used to be like that, which is why I started looking into it myself.

Quran absolutely promotes horrible negativity if you want it to.

Exactly. If you want it to is the key sentence here, if I want the bible to promote negativity I will interpret it in a sick way to justify my actions. Which is exactly what the sick bastards in isis and terrorist groups are doing. Keep in mind that the people in Pakistan/Afghanistan are most of the time illiterate, and their first language is Urdu not even Arabic, so if an ill minded leader (Fazlullah) says that the Quran promotes war against the western people, the citizens would believe that, because they are not educated enough to read the Quran and interpret it in their own way. Which is what people like you are doing, interpreting the Quran from someone who claims to know when they actually don't.