I had a few minutes to review that stuff.
Assuming UFOs and extraterrestrials and their technology do exist.
Apparently the authors consider it bad to shoot down UFOs (ETVs) for plunder.
If so, we should forget about using technology that we found on the ETVs we happened to shoot down. If they want to give the technology to us, they can easily do so. If they don't, stealing their technology is not going to make a positive impression on them.
For ETs providing us with technology as a way of survival is equivalent to making us their pets. I am sure that if they flew all the way here and they needed pets, they could get much nicer and less messier ones then humans. If some pervert ETs do want to keep some human pets, they would probably keep abducting single backcountry humans rather then feeding and housing the whole planetfull. In that light it makes sence them not abducting prominent scientists, financieres and politicians - those are boring. Would you choose Alan Greenspan as a pet or some backcountry bimbo?

The powerfull secret clique is the best depository for all super-technology I could think of. They are most likely powerfull, intelligent, educated and stable people that would not feel a need to blow up a planet without a good reason. Kind of like a monarchy or oligarchy. Interested in preserving the planet for their children.
On the other hand, giving a source of unlimited power to anyone asking for it is bound to end in someone blowing us all up.
Of course the authors mention control, but do you realise what kind of control would be needed considering that the stake is a total annihilation of the planet? Total police state! No democracy whatsoever, total surveilance, thought/emotion monitoring, isolation/elimination of mentally unstable or politically radical people, etc.
I guess that evil clique that has the technology does not want that to happen. They also do not take over the power overtly with all their super-weapons. So they probably like to keep as much democracy as possible considering the circumstances.
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Antigravity, zero-state energy:
Energy is directly linked to mass and curvature of space. Do I want some neighbour's kid tinkering with the curvature of space I live in and/or affecting the mass of the Earth every time he rolls his hovercraft out of his garage? I don't think so...
As for disclosure, how about disclosing to people that contrary to many religious books, there is a pretty good evidence that Earth has existed for longer then 5 thousand years?
That info is freely available and many people do not really care or assume it's god's will for it to appear so, so why would anybody be interested in extra-terrestrials?
For religious people, everything is in His power.
For the rest of us, ETs will announce themselves when they see fit.
If you believe in that technology and want it, why don't you go into science and try to discover it yourself?
If the Earth is in danger from our activities and you care to save it, you should not rely on outside help. For all we know, ETs are just waiting for us to die out naturaly while their sub-light colonizers are on the way...
Also, there will always be powerfull people and less powerfull people. That is the law of nature.
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miko