This is getting interesting and I respect your position.
However, "the natural rights of man" is indeed a very Western thing since maybe say ... the French Revolution? I would guess. Yet, if I undertood what I read properly, I would have to say that the philosophical/religious foundation of "natural rights of man" has indeed been derived from Christianity. Why would I say this? Because in Christian mythology, it is believed that God placed man on earth to do his own thing with his free will. Anyway, to make long story short ... along comes a dude name St. Ausgtine and writes some stuff noting the "progress of man" being closer to god by learning about our environemnt and going to school and hence the old universities had close links to the churches. In fact, universities were runned by the clergy and churches. So, the more you learn and know, the closer to god one is. Okay, pause that for a sec ....
Another important thing Augustine wrote was the perfectablity of man. How is this achieved? Again, to make a long store short ... man does so by "progressing". This is done by being closer to god and to "reveal" the unknown and to be "better" then those before us and to learn about God himself (e.g. know the Bible).
Then along comes Hegel who really believes in progress. He states that the end goal of human history (as noted in his "Philosophy of History") is freedom and that this freedom has three stages: the Oriental stage, the Greek stage and lastly and finally the Germanic stage.
If we look at this collectively, Augstine who is highly influential using Aristilian logic and the Christian faith has basically molded the character of Western civilization. And if we add Hegel ... it only strengthens the Christian belief that man is in fact "perfectable" and that humans actually "progress". These are the foundations which lead up to the belief in "the natural rights of man" ...... meaning that we believe there is something inherent in mankind, that we have the intellect to do our own thing ...
Again, this clearly means that natural rights is grounded in Christian mythology.
Nonetheless, as Nieztsche notes, human progress could possibly only be a "myth". The only way man can progress is when he is "transforming" into the superman or be degraded to the "last man". And it is this last man that Nietzsche is afraid the human race would fall to.
Yes Heidegger was a Nazi Party member but it does not make him a "bad philosopher". Ezna Pound was a fascist, George Bernard Shaw also believed in elements of elitism ... but so what? Does it make their works "bad"?
Again, I do not mean to use Nietzsche to back up my argument, but ... "how life preserving? how species advancing?" is natural rights of man? Whatever the hell you want to call it, as long as it is life advancing and specie advancing, it is in fact "beyond good and evil".
Natural rights of man is based on the individual. But what if someone believes in the collective? Again we have the un-debatable-never ending dicussion of individual Vs. collective ...
BTW, although Heidegger was anti-tech. he wa not a "primitivist" like you said he was. Heidegger was a guy who believed in reviving the glory, ideas, and spirit of the ancient Greeks. But that does not make him a primitivist ...
Furthermore, postmodern thought does not hate everything Western. In fact, postmodernism came out of the West (but could be compared to Taoism, Zen and other Eastern schools of thought). Postmodernism was "born in France" and the French had always been a group of people who spearheaded new philosophical thoughts into Germany, and then the rest of Europe.
When you are talking about the natural rights of man ..... do not forget its French origins, its Christian roots and hence a Western way of looking at mankind ...
PS - if you dislike postermodernsim, then I would believe you are not a relativist ... in that sense, you would only believe in one universal truth and that there is only one defining character which makes something "beautiful" or aesthetically appealing. Do you like art? Is art "good" or "bad"?
Thanks