Like Christians and Jews, the other people of the Book, Muslims consider those who are not members of their religion to be outsiders. At assorted times in the histories of both religions (for the Jews, very early), non-believers have been persecuted and killed. Christians of some persuasions are still persecuting non-believers.

I went looking for your guy's reference to the Unclean in his article. Surprise! It isn't there! There is considerable discussion of najis, when something pure becomes contaminated through contact with unclean things used by non-believers. For example, some soaps are made with pork fat derivatives. Can a Muslim use a laundromat also used by non-believers if some may have used such soap in the machines? What if someone has washed clothes contaminated with urine or blood (both very najis) in the machines? These are rules very much like the rules governing kosher foods and the rules that used to govern eating meat on specific occasions in the Catholic tradition: arcane, without much meaning to those not of the religion, but not dangerous.

He mentions that chess is forbidden. This is true, but the reason cited is that people bet on chess games. Silly? I think so. Dangerous? No.

I didn't have to go far on the site to find this [emphasis mine]:

In The Name of Allah The Merciful The Most Compassionate

As part of the cycle of criminal acts witnessed in beloved Iraq, targeting its unity, stability and independence, a number of Christian churches in Baghdad and Mosul were viciously attacked - leading to tens of innocent victims falling dead and wounded as well as the destruction of many public and private properties.

While we disapprove and condemn such abhorrent crimes and see the necessity to consolidate efforts and cooperation by everyone – government and people – in order to stop attacks against Iraqis and root out the attackers; we stress the need to respect the rights of Christians and other religious minorities. Among these rights are their right to live in their country, Iraq, in peace and security.

We ask Allah The Almighty, The Omnipotent, to protect all Iraqis from harm and misfortune and to bless this beloved country with security and stability, He is All Hearing and [He] Answers Prayers.

Office of Ayatullah Seestani – Najaf

15 Jumada al-Thani 1425
2 August 2004

Specific injunctions against lying to, stealing from, and defrauding non-believers can be found here.

Your guy gave you the source, and then distorted what he found there. Next time, go to the source yourself.