A very good summary. From my side, I'll add a couple of pointers and addendums to this, on the technological side of things (as I an Orthodox Materialist
. As I refuse to treat Dune as a fantasy novel.
AI/Circuitry/Computers: We're only about 100 years into the Age of Electronics. From the engineering standpoint, we have, in all likeness, NOT a clue about how their circuitry looks or works. Therefore we must take literally "No Thinking Machines in the likeness of Man", and NOT think in the terms of what we consider electronics/computers today (transistors, integrated circuits, digitalism), but in the terms of what was the meaning of these words in the culture of Dune, some 20k years in the future.
Genetic Memory: Highly advanced biotechnology with a sprinkle of social conditioning. At some point in that abyss of time, some humans (nobility perhaps?) were enhanced in a way that created the penomenon. Tlailax (a Male order, am I wrong? No female Mentats!) being a likely culprit, on a rare occassion they cooperated with Bene Gesserit. One specialize in Mind, the others in Body.
The Power of Voice: Widespread mental conditioning. The Gesserit were in charge of the highest culture for
Millenia. It is not unlikely they have slowly brainwashed the masses to be susceptible to the power of hypnosis. This is proven possible by science. All more likely since there were persons (Vlad Harkonnen) and even whole nations (Fremen; an isolated group) which were to various extent resistant.
Holzman Shield Generators: I don't want to bore you, so in short, what can sustain such considerable power for basically infinity and violently explode when interacted with in a certain way (a focused, high powered ray of electromagnetic radiation), with a force of a thermonuclear bomb? Easy. Thermonuclear reactor. Again, one current school of possible fusion reactor design is so-called 'Polywell' (
https://en.wikipedia.org/wiki/Polywell ). It could be miniaturized. No battery could hold out for infinity, while a fusion reactor, which can procure hydrogen from its sorroundings, could. However, such a reactor doesn't really need a digital computer, it can have an immensely sophisticated analogue circuitry instead. But to us, it'd look so much more primitive and yet much more intricate than our best computers.
Holzman Platform, Glow-globe: same power source, but antigravity? Who knows. Gravitational radiation has been discovered, albeit just only very recently. It is big news in physics. If there is radiation, there can be a way to inreact with it. Not disproven!
Prophetic Powers: Science as of today knows very little about the true capabilities of human mind. Or the ways to enhance it to superhuman levels. And we might never know, as only a more complex system can fully model a simpler system, but we don't have any more complex system than our brain, so we don't have anything to fully model it on! In all probability, the enhancement of the human brain in the future will be trial-and-error process. The point is, there is no way of telling what an enhanced human brain would be capable of.
And yeah, tiny clockworks can work too as circuitry, but I believe, without proof, that electricity and magnetism will prevail in the end
No myth has been busted in this slightly humorous yet serious summary. Dune is not a Myth! It's Science Fiction!
(and I won't start a Jihad over this either, cross my heart
)