Went through your list. I didn’t get the sense of deep belief in communism nor antiamericanism. There seemed to be other incentives. Is there a good example?
Not OP, but I would recommend on this subject a podcast I've talked about in a previous comment [1], about the life or Hoover and the red scare in light of declassified knowledge of soviet spies in the US.
I don't think you studied either Klaus Fuchs or the Rosenbergs in much detail then. Whatever the merits of their actions or the cases against them, they were certainly dedicated Communists who did their best for a cause they believed in fervently.
I should have been clear — those were the 3
Wikipedia isn't the right source for "the sense of deep belief", it's far too dry and factual for that.
The Rosenbergs were known as believers in Communism.