Pax Aineo.
True the history of the Catholic Church hasnt been pretty, name one religion that has!. You talked about the Crusades as if they were a bad thing, Im guessing you know somethings but not why they really happened. Many say it was for imperialism, to statisify the Kings of Europe with land etc. Well Ive heard this so often it kind of astounds me that these people that believe this total ignore the Severe danger that was all throughout europe, as well as to Christian Brothers in Palestine.
The Crusades were defensive. Just look up Islamic Conquest 7th-11th century, and then you can see why the Crusades happened. Try getting a book called "The Knights Templars" it portrays a gruesome lifestyle of Christians under the Reign of Islam.
Ill list a few:
Churches ransacked, burnt and pillaged.
Priests, nuns, deacons beheaded, raped, or hanged.
Restrictions of Shariah Law - Must bow to a Muslim as passing and pay a 'tribute tax' Jizya i think its called.
The expansion of Islam into Europe, Spain alone had 114,000 Christian martyers.
This is just the top of the icing.
You said the Crusades were against Christ's Teaching. Heres something to think about:
If the crusades, european offensive against Islam didnt happen, do you really think Christianity would still exist today?, and you'd be preaching your "Catholic Imperialism" stuff?
Look to the history of Arabia, Turkey, Africa, India, Spain. The Armeans were a recent genocide by Turkish Muslims, 2million wiped out.