Yes and only that. Unless they're a Tek Heretek, even a radical Archmagos wouldn't risk reviving a Man of Iron, not without some serious precautions to prevent the corruption of Chaos. Perhaps building a laboratory in the same way you'd build a Navigator's Sanctum which would then be stored in an even greater Sanctum and even then, it's very likely to find that Chaos would find a way through. But radicals are radicals so they may think it would be worth the risk. Probably have a torpedo warhead or five under the facility ready to detonate at a moment's notice.
What? No. No one would give a shit. So long as the AI or whatever technology is there that stores the Abominable Intelligence is either destroyed or non-existent, they most likely wouldn't give a shit. The power source/reactor, weapons, articulation designs are what they'd want. Metallurgy, that kind of thing.
It's just far too dangerous to risk. The Men of Iron caused a war that spanned the entire galaxy and it happened before the Age of Strife. Before the Eldar hate-fucked a Chaos God into existence. The Mechanicus have a formula to determine how quickly AI will turn on their creators and it's depressingly accurate. Most machine intelligences (known as machine spirits) are based off of animals so as not to gain enough sentience to properly rebel.
What tech exactly? The ones mentioned previously? Yeah, sure, they'd be all for that. Whatever powers the Men of Iron would make an Archmagos unimaginably rich if he could produce it reliably. Assuming he can come up with a credible story for how he acquired it. Otherwise he or she would be lobotomized into being a servitor or reduced to a servoskull.
You're giving the Mechanicus too much credit in terms of empathy or compassion. If it took the death of every single life on a planet to recover an Imperator Titan, they'd ask you why phrased that as a question while preparing the life-eater virus bombs.
Ah, I see what you're getting at. I had assumed that they'd been pure or untainted. If the equipment was tainted then obliterated from orbit would be the outcome from either a radical or a puritan.