Here are some videos about Kundalini -
One thing about kundalini and all yoga. Five thousand years ago there was essentially a single system. Five thousand years ago or so this found its way into writing. It was far older as an oral tradition. For an oral tradition to find its way into writing means there was probably concern about corruption. Indications are that the original system started fragmenting because after it was put to writing as the Rig Veda, all sorts of commentaries and interpretations and philosophies sprang, meaning to original poetic symbolism was not sufficient for understanding to perpetuate.
Over time, Indian society went through many transformations, the priests became corrupt, Buddhism sprang to counter that, Advaita Vedanta (non-dualism) sprang to counter Buddhism, Tantra come into writing to counter the Vedanta forms etc. The original Vedic wisdom, which has been misrepresented by the English scholars, influencing the Indians themselves to question their own traditions, fragmented so that one chapter of the Vedas would become a tradition on its own (although you can't really organize the Vedas into thematic sections easily).
Thus all these people speaking of kundalini yoga emphasize something and diminish something else. In addition, the yoga taught to westerners is not quite the same as the yoga tought to nationals, at least in some cases. For example, most of the west are of a Shavait tradition. To them reality is leaving Shakti to go to Shiva. Shakti is like an elevator lift taking you out of Shakti at the top floor. For Shakti traditions the meaning of life is the to have the pie and eat it too, to merge Shakti and Shiva in life, in the body and interpret Maya (form) as Lila (play). Basically the Divine essence created the world to have a good time. It's just that in the process of creation the worldly divine divorced from Itself. That doesn't mean game over, but that the essence is finding itself to remember why it started the game in the first place: because it's Worth It.
I think it's going to take some time to bring the wisdom at the level of the original post Ice Age civilizations that developed it. Many of these are under water, and the Vedas speak that over time some corrupted the wisdom and became "demons" (basically power mad psychopaths packing a punch). Conflicts resulted that further messed with the world. Cities were destroyed, civilizations collapsed, yet there is not archeological evidence that there were any wars outside of barbarians invading an already beaten culture.
The point is we assume this wisdom is something complete and authorized when there are more than a few contradictions between sects and factions. They are not like the Monotheists who go ballistic over every crossing of the t and dotting of the i, and they prefer to show a unified front especially in front of westerners. But each of these sects emphasizes a piece of a greater picture. What the women in the interviews (the two in the first ones and bubbly AnnaBrett) said was true, but in some cases I would say "yes and no" or maybe add a footnote under a few phrases.
For one, Ramana Maharshi (the initiator of the particular Shavait lineage in the second video) was a Jnani, or Gnostic Yogi. Jnana doesn't deal with kundalini, although it can incorporate it. Jnana is Gnosis, the immersion in the realization of the Absolute. The idea here that once you attain this realization, you will be enlightened as to how to continue. It doesn't end there, except for those whose purpose is to emphasize that aspect of the Greater Path.
Most religions started as Bhakti or Worship yoga. Bhakti is the foundation of the inner center, and is built on relating to the divine at the soul level. This amounts to opening the heart to love and reverence, which has been misconstrued as religious groveling over time, and later with judgmental deities and people acting as the representatives of gods etc. Religions are a manifestation of Bhakti yoga, and often a perversion of it. Hate and intolerance after all are the contradiction of Love and Acceptance.
Hatha yoga retained elements of Vedic martial arts, which later were adopted by some Buddhist converts and taken to China to fuse with shamanic martial arts of Taoism. Even those were innovations of partial knowledge. What was lost was compensated. For example, there are Hatha yogis who will sever the flap is skin under the tongue so they can put its tip on their 3rd eye and open it more directly.
Kundalini Yoga proper goes by many names, including Laya Yoga, Kriya Yoga, the methods of Tantra and Mantra Shastra.
Laya yoga is the yoga to which the older women of the interviews refer. It means yoga of dissolution http://en.wikipedia.org/wiki/Laya_yoga . It's purpose is to decondition the self until only the Absolute remains. Kundalini is the path to the Absolute, which is the Goal. Kriya (movement) yoga is a specific revival brought to the west in the 20th century by Paramhamsa Yogananda, which incorporates mostly breath energy methods, but you need to join the group to get the specific info on what these are. There is Raja Yoga based on the Aphorisms of Patnajali written in the 5th cent. BCE, and which deals mostly with concentration with posture, proper conduct, breath work supporting it to lead to divine union. There is Karma Yoga, with is meditating by offering all your actions as sacrament, so that every moment is a meditation without ritual or specific technique. Even in this kundalini can awaken if one is ready.
Tantra is actually very close to the Vedic wisdoms, and in continuity with them, and hard to define because of the many variations, right, left, Shakti, Shiva etc. The main difference is that Tantra believes enlightenment and enjoyment of life should not compromise each other, and that kundalini is a cornerstone of Tantric practices. Although many of these claim to contradict allegedly Vedic practices, they as well as all the various sects and anything written after the Vedas, are a continuation of putting a formerly oral tradition in writing, even if over time there was fragmentation and factionalism, which for a westerner can be confusing, but which Indians tend to take in stride as far as I know.
For example, while smiling Anna Bret prances around claiming kundalini yoga is perfectly safe, the Tantric guru will tell you that you will be cast into hell if you attempt it outside of the tradition. Some advice that you need a guru and some say the inner guru is all that's needed. The point is that kundalini may have retained Indian terms because other traditions have been lost, but it a human heritage, and even if it worked ten thousand years ago, things are different now and the wisdom needs to be built again as it was a long time ago.
One thing I believe is that more people have symptoms of spiritual awakening today because of modern conditions and the increase of stimuli in our lives compared to the past. There are so many taking antipsychotics and antidepressants now because of such symptoms. These do not just make people turn to drugs, they freak out everyone else who feels threatened by the energy to promote the drugs. So in a sense, getting a handle on this wisdom in a way that reflects our historic and cultural conditions is important. Like it or not, evolution can't be put on hold, so we may as well work with it.