Well it is in that Yungdrung Bön was "first" in two senses: A) Yungdrung as you know means 'Eternal' or Unchanging and B) according to Yungdrung Bön, Yungdrung Bön began in this cycle about 18,000 years ago. So what I'm saying in this sense is that without Yungdrung Bön appearing on this planet 18,000 years ago, Black Bön would have never come about, for better or for worse; even though there was likely very little remnants from the original Yungdrung Bön to be found in the corrupted Black Bön schools
Well this does not fit with how Bon envisions its own history. According to Bon, Yungdrung Bon is the Bon of Tönpa Shenrab and Tönpa Shenrab came to Tibet once where he is said to have converted Bonpos there. These Bonpos were from the Old Bon. So Old Bon which has nothing to do with modern Bon (Yungdrung Bon) pre-existed at a time before Yungdrung Bon.
Whatever old material dealing with "Bon" in general and dating from Dunhuang that we have belongs to Old Bon, there was no Yungdrung Bon at the time, or at least no reference to it in the mss available from the Dunhuang caches. As to the date of 18,000 years, it has no historical value at all. It is a number which has another aim and should not be taken as a litteral one.
doesn't always necessarily imply negativity according to Vajranatha).
Vajranatha's fancies about Bon have no historical background at all. He is not an historian and I would not trust a second most of his views about Bon, be it Yungdrung or Old or whatever.
(And like you said, Yungdrung Bön as it is taught now, is a Sarma school)
Sure, modern Yungdrung Bon is a Sarma School, probably the closest to Geluks. They have similar curriculums and tantric ideas, not to mention prasangikas philosophy, etc. The only difference in the training of the two schools is that Yungdrung Bon has Dzogchen at the end of the curriculum.
18,000 years may or may not be literal,
It should not be taken literally, it comes from a confused calculation taking into account Shen-years and conflicting early sources differing in the year Tönpa Shenrab was born. Sticking to it will only bring in confusion. I know Yongdzin Rinpoche holds it very tightly and considers it nearly as a doctrinal data but, hey, there was no civilization as that described in OLmo Lungring in that part of the world (or any other part of the world) 18,000 years ago.
And interestingly, it is said that Heruka Bhagavan Sri Ngondzog Gyalpo taught here over 5,000 years ago.
This is faith, not history. We have not a single historical document dating back 5000 years ago mentionning Ngondzok Gyelpo...
It looks like there that Guru Rinpoche was distinguishing Yungdrung Bönpo's from the groups that practiced Black Bön only.
Yes he does, but there was no such things as Yungdrung Bonpos and their monasteries, canon, etc. during the time of Guru Rinpoche. There is not a single historical evidence of Yungdrung Bon existing before the post-dynastic era. No ruins of former monasteries, etc. If you look at John Bellezza's paper in the RET (http://himalaya.socanth.cam.ac.uk/colle ... _19_03.pdf
) you will have a surprising picture of Tönpa Shenrab according to some of the earliest sources mentioning him (and quite in conformity with the scanty sources mentioning him in the Dunhuang documents).
Then Yungdrung Bön also includes White Bön?
White Bon is not a doxographical entity in Bon works. It is a buddhist expression which was rejected by Bonpos themselves. However, in Eastern Tibet, you will find Bon works using that expression (zhwa dkar g.yung drung bon, Eternal Bon white Hats) which is probably derived from it. However, normally Bonpos don't use that. They use: Old Bon, Eternal Bon, and New Bon.
And when people say "Old Bön", are they usually referring to "Black Bön"? Or do some people say "Old Bön" as to refer to Yungdrung Bön?
I don't know which "people" you are referring to here. As said above, Bonpos use: Old Bon, Eternal Bon and New Bon.
From what I understand, Old Bön usually refers to the Black Bön groups.
It's also interesting that Bön as you pointed out has in a sense more in common with Gelug than it does Nyingma.
Sure, Bon is a Geluk school which has Dzogchen in its curriculum. mNyam-med Shes-rab rgyal-mtshan played a crucial role in re-formating Bon according to monastic criteria (before that Bon was mostly handed over through lay families or familial clans). His encounter with Tsongkhapa and the praise that Tsongkhapa wrote to him are important elements that shaped this monastic form of Bon (even if there were of course monastic rules and a very long monastic history in Bon prior to that).
Although like I said before, Yungdrung Bön expresses the essence of the teachings of the Buddha Shakyamuni more than Gelug, Sakya, and Kagyu do; considering that Dzogchen is the main teaching of Yungdrung Bön and that the Buddha Shakyamuni is one of the Twelve Dzogchen Teachers.
This comes from late termas (14th century at best). Before that Shakyamuni is not associated with Dzogchen at all. You have that list in Dorje Lingpa's lTa ba klong-yangs for instance but this list is probably influenced by a non-similar list from Bon. Other than that, Nyingthiks do NOT abound in references to these 12 teachers. There are some, sure, but it's not as widespread or frequent as one may think it is. I guess you have more Dzogchen cycles which do not mention that list than the contrary.
Sangyé (sangs-rgyas) teaches the teachings that lead to Liberation from samsara, whether we say Chös or Bön.
Sure but personally I don't trust that distinctions between Chos and Bon, Chospa and Bonpo, etc. Bon is Buddhist because it follows the teachings of a Buddha, it is a Sarma school now and one of the most active religious tradition in Eastern Tibet nowadays.