Thank you for a powerful post - and one needful in these times.
The history of the connection between Islam and Christianity is far more complex, as you say, than the modern caricature has it. After all, St. John Damascene worked for the Sultan and was freer to write than he might have been under an iconoclast ruler.
That is not to excuse, or deny, the crimes committed in the name of Islam; but we have to be mindful that Muslims are not alone in this plight. What the Crusaders did in 1204 in Constantinople was a very great crime. The way in which the Chalcedonians treated the non-Chalcedonians after 451 was hardly an example of Christian behaviour we would want to cite as a model to be followed, either.
The activities of the Catholic and Protestant missionaries in the Middle East in the nineteenth and early twentieth century arguably did as much harm as good, and the way in which both the Copts and the Syriac Church were treated - 'lesser Churches', was not helpful to people whose Christian history went back to Apostolic times; neither has the Allied intervention in Iraq done much to help an equally ancient Christian community.
I am not defending the infamous conduct of some Muslims - the treatment of the Armenians by the Ottomans (intentional or not) was the first holocaust of the twentieth century, but your reminder Kirk, that there are other histories of Christian-Muslim relations, is a good and timely one - for which, thanks.
In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins. (1 John 4:10)