In my opinion, the first thing to take into consideration is that Guenon and others of the traditional school are not dealing first and foremost with texts and the dispute concerning their authenticity or the veracity of their contents, but rather with living traditions and the consideration of orthodoxy in light of an understanding of traditional metaphysics. There are a variety of internal and external factors that can be used in the application of sound judgement in these matters and you will find many discussions on these in the present section of our forums to which I have moved your post. Of course, the easiest way to make such an assessment is to engage oneself in the fullest manner possible with a living orthodox tradition as this will give one access to God and thereby to the implicit capability of discerning the diverse manifestations of His influence. Participation in one of God's revelations brings with it the possibility of bearing witness to others. The excessive rationality that characterizes modern thought can serve as an obstacle to the humility required of such participation. One of the functions of many of the books written by these sagacious teachers is to meet the rational man at his own level by the application of superior arguments, in reality very ancient teachings couched in a new discursive form, and ultimately to delineate a path leading from ratiocinative apprehension to intellectual intuition. It may be helpful to you to read one or two of these books that are concerned with exposing the psuedo-intellectual foundations of modernity such as Rene Guenon's The Crisis of the Modern World and The Reign of Quantity of the Signs of the Times in addition to a good summa of the traditional perspective of which I consider Nasr's Knowledge and the Sacred to be the best ...
Guenon's early assertion of the heterodoxy of Buddhism was based upon his predisposition toward the Vedanta and assimilation of its early conflict with the Madhyamika school of Buddhism. He later rescinded this assertion largely due to the influence of two of his prominent correspondents, Ananda Coomaraswamy and Marco Pallis. Concerning reincarnation, he rejected the popular notion of the soul continuing a cyclic return to the habitation of the physical body and instead understood it as posthumously inhabiting different states or levels of being which are mythologically represented in Hinduism and Buddhism as the various heavens and hells. Although I am somewhat skeptical of most contemporary writers who refer to themselves as traditionalists, especially those who have been "riding the tiger", my own interviews with the followers of Bahá'u'lláh have led me to the understanding that their doctrine is erected quite self-consciously upon the twin pillars of modernity, evolution and progress, couched within an eschatological framework and crowned by a universalist sentimentalism.
I hope that you are able to find something useful among these thoughts, and I look forward to further discussions with you on our forums.
Greetings of Peace. This blog contains selections from my correspondence and other sources on a variety of subjects related to religion, philosophy, and spirituality. I hope that they may be of benefit to the interested reader. Concerning the title of the blog, read this entry.