I don't think a straightforward criticism of the veracity of the Bible has been relevant in the thread, we have been discussing the excesses of its fundamentalist adherents.
In any case blaming all of these things on Christianity is easy but is grossly inaccurate. The crusades were in part done by most who participated for land, wealth and power and in part in response to repeated invasions by muslims (done for land, wealth and power). Christianity gave the pope control of the whole deal but there is no reason to assume the same wouldnt have happened if it was any other religion.
The dark ages happened when Rome fell and there was a power vacuum and are called Dark due to a lack of written records. There were lots of battles and suffering and lots of people were Christian but I don't think a lack of Christianity would have helped, especially since Islam was the competing religion.
Wiping out the Indians was done for land, slaves were taken for economic gain, the holocaust was done because Hitler was a fucking nutcase but not with great religious conviction, the gulf war and every 20th century war was about oil, land, power, money, security and/or political ideology as you have partially stated.
I'll give you the inquisition, and I'll throw in the persecution of scientists like Galileo but the other things had far more important reasons than Christianity, and I'd wager most would have happened without it. I can in a sense see how the more fundamental Christianity practised in places like Africa and South America causes serious damage though, every religion seems to advocate abstinence (which doesnt work, hence widespread AIDS) and subjugation of minorities (including women) in the places it is practised in its more severe forms.