You can't generally clone psykers. Clones already don't work well in 40k because they follow dystopian sci fi cloning rules, they tend to be duller, mutated or otherwise wrong. Psykers then add having warp altered genetics into the mix and it all goes wrong.
You also can't generally isolate psykers from the influence of the Warp and still have them be psykers, since that connection to the Warp is what makes them psykers. Putting them in a state of sensory deprivation just tunes out everything except the corrupting influences.
Then just mass produce them with IVF, and intervene in the gestation. If they can reliably have psyker babies, then IVF would work too.
They can't. That's why the Black Ships are a thing.
Heh I was going to suggest that the only way to reliably acquire psykers would be to devote entire planets to reproduction and screening. And then most of that "product" would only really be useful as fodder for some incorruptible psyker somewhere
As for chaos infection in general, my understanding is that it can creep in anywhere, but it requires substantial local corruption for daemons to really start manifesting stuff. Hence cults form, worship in secret, eventually manage to pull some lesser daemon through, things potentially snowball from there.
Machine spirits and their potential for corruption are definitely interesting to think about though. The Imperium's reliance on Geiger-esque biomechanical control systems (brain in jars) rather than Abominable Intelligence seems to explain why chaos can get in. Which makes me wonder if it CAN get into pure AI systems. I have little basis for this, but here's what I like to believe: The Men of Iron incident was unrelated to Chaos, more a Skynet situation. An AI singularity which, for one of countless reasons, became hostile to humankind. It could easily have been another Necron computer virus, particularly with that C'tan on Mars, but I prefer to think we just created something unique that got away from us (and was repulsed by us, or us by it).
End result: An outright ban on inorganic AI, and resounding technophobia (whatever happened, the incident was *devastating* for humanity). If I'm right, a daemon would have an easier time possessing a bed than a pure AI. Sure belief-magic would give it a soul, but it would be a soul/expectation of cold logic. Hence resistant to emotional manipulation. I suppose Tzeentch's line would have the easiest time understanding and working with such a thing...
But in any case it wouldn't matter, because true AI is inherently malicious to Humanity in this setting. Just one of the defining aspects, it'd be pointless to question it.
...probably