He's connected with liberation theology, which is what the KGB was promoting in Catholic countries to recruit for militant groups. Similar to how they promoted revolutionary Islam to people like Goddafi. I think the Soviets actually claim to have invented liberation theology, but who knows.
His deschooling and Limits to Medicine stuff were standard Soviet tropes and still are today. The obvious purposes are to get the US to weaken its education and medical systems. They ran similar strategies to get the US to weaken its nuclear system and to me it looks like they're also trying to weaken adoption of AI through similar ideas. But basically schools are bad, medicine is bad. Claims we're "pathologizing" everything. You see the same ideas in socialist spaces online today. Especially these days around psychology. Similarly with the "factory school" trope.
When Energy and Equity was written in 1974 it was a year after the 1973 oil crisis. The Soviet Union was destabilizing countries in the middle east and wanted to secure access to oil especially at the expense of the US. Their normal propaganda would be about American imperialism and how they're evil and oil producing countries should side with the Soviet Union instead. I haven't read the book, but that would be the Soviet take at the time.
I don't know whether he was supported by the Soviets. He was a public intellectual who traveled a lot especially to South America. It's very likely he was approached and attempted to be recruited by the KGB. But whether he rebuffed them or not isn't public knowledge.
One thing we're learning as more stuff gets declassified is how many household names were more actively involved in the cold war than we realized. For example, Howard Zinn being actively involved in communist organizations despite lying about it for years. Or Earnest Hemingway actively collaborating with the KGB (although in the end wasn't very successful). There are a few other examples.