You certainly pose interesting questions.

Guru is generally a term used by Hindus and sometimes Buddhists.  It described the person's teacher, someone they submit to spiritually.  As I understand it, and I may not, it usually means accepting the guru's particular beliefs about things.  A Catholic spiritual director should not be demanding submission to his own way of looking at things, to his own cult if you will, but helping people to conform to the teaching of Christ and His Church.

I guess you could look at it that way.  It has always seemed to me that guru's in eastern religions often claim a level of devotion from their followers that it is dangers on a simply personal level for any mere mortal to claim.  That is to say nothing of the specific false doctrines they might teach.

Why would you want to used a term like "guru" anyway, even relating to Christ?  

Yes, Guru just means teacher. I'm from India, so I know this one. :-) Sort of like "rabbi", I guess, in the Hebrew.

The Jesuit missionaries had no problem adapting indigenous terms to describe Christ, the Saints, etc.

In Vietnam the term "tien-su" (from the Chinese: "h'sian-t'zu") was used to describe men like Confucius, Lao-tzu, or even just a teacher.  It literally means "former [born]" (tien) "master/teacher" (su). Confucianists also called Confucius "tien-thanh" (from the Chinese: "h'sian sheng"), "thanh" meaning "saint" (as in the Latin definition of the word which can be used either as a noun or adjective).

While Alexandre de Rhodes forbid Catholic converts to refer to Confucius in this way, he had no problem applying the same terms to describe Christ. In fact, the title to describe the mother of Confucius, "thanh-mau" (from the Chinese: "sheng-mou"), lit. "holy mother, is identical to the title used for the Blessed Virgin.

The Vietnamese title "Duc" (from the Chinese: "de"), meaning virtue or virtuous, which was used for men regarded as holy, was applied to Christ, the Blessed Virgin, the Saints, and many other things in the faith as well.

I've never heard anyone call Christ "dai-su" (great master) or "tien-su" since those terms are now mainly used by Buddhists and Catholicism isn't that alien to the culture anymore, thus eliminating the need for native  vocabulary.

The Jesuits also had no problem "changing" the Bible. There are no deserts in Vietnam so when refering to Christ's fast in the desert, they said that Christ withdrew to a deserted forested mountain. In the Orient, the tradition of men withdrawing to seclusion in forest mountains to do penance and enter into meditation in so ancient that the Chinese character, "h'sien" (meaning an "immortal" demi-god, or a mystical person) is the character for "man" side-by-side with the character for "mountain".

It should also be mentioned that the idea of having "spiritual fathers" or "Fathers" aside from your biological father is so ingrained in Vietnamese culture that until the 20th century the word "thay" was used to describe one's father, one's male teacher, and priests/religious. The Protestant argument is here inimical to centuries of culture.

Even more interesting is the translation of the word "Holy Mass". In Vietnamese it is "thanh-le", from the Chinese "sheng-li". Sheng means "holy", Li means ritual.

Li is used to describe any type of ritual. Marriage, funeral, etc. Confucius speaks of the importance of the various "li" in for the well-being of society.

So the translation of Holy Mass is literally "holy ritual".

I was confused when speaking with a Buddhist. She was speaking to her Catholic friend and saying that if her friend died she would "xin le" (lit. ask [for] a ritual [to be performed) for her soul) for her. The thing is that Catholics use the same term to say "have a mass said for...". So the idea of having Masses said for the repose of the deceased and for spiritual/earthly blessings for the living is also very deeply ingrained in Oriental culture.