If your point is that relying strictly on the holy texts of a given religion, one might come to a misunderstanding about the nature of that religion, I'd agree. Surely the sacred text of Christianity condoned, at one time, much violence. It isn't even good enough to point out the difference between the Old Testament and New and claim that Jesus brought a whole new understanding. While that is true in theological terms, there was still plenty of violence in the name of a particular religious viewpoint.
However, I don't think it is reasonable to stretch the point too far. For the most part, the Enlightenment, with its emphasis on the individual rights of man and the division of the temporal world into religious and secular spheres, created a situation where for the most part, we've gotten past our own proclivities to violence. True, there are exceptions, but the days of Christians fighting Christians over a given religious interpretation are for the most part over. We also don't generally fight other religions in order to forcibly convert its followers. So while it is important to point out that Christianity's hands are not clean in respect to violence, I don't think it is fair to imply that this case is now somehow the general situation today. In my experience, I don't see radical Christians committing terror against Muslims for the sake of religion.
In that same vein, it is reasonable to point out that Muslims have not achieved that state of pacific accommodation within Islam, let alone with the outside world. These days, fundamental Christianity does not require the death of others. I don't think the same can be said about Islam. Historically, whenever Islam or Christianity has felt its existence threatened, they have retreated into extreme conservatism. The difference is that for Christianity today, extreme conservatism is nonviolent. We've made the journey to God an interior one. Islam, when it retrenches, still turns just as violent as it did 1000 years ago.
No one can ignore our own religious history. However, we must also not ignore the fact that Christianity, for the most part, has left many of these notions you cite behind and evolved into a bifurcated system where religious doctrine does not directly guide secular policy. I see Islam as attempting the exact opposite - their desired state of existence is one where there is no difference between the law of God and the law of man. That is a crucial difference in my opinion between the two religions. Such a fundamental difference in outlook cannot be overstated. For me, it drives much of the misperceptions our two religions have of each other.
