I can answer the last subquestion on the intelligence view.

McCarthyism, referred to as "spy mania" by Moscow Centre, was perceived by Soviet Intelligence be a condition which would make it far more difficult for "Legal residencies" to operate on U.S. Soil. (A legal residency is an intelligence network that communicates by intelligence officers with diplomatic cover and typically operates out of embassies and consulates.) Accordingly, Moscow Centre spent great effort in the 1950s, 1960s and 1970s to create illegal residencies, or establish officers under civillian cover living on US soil who could recruit agents. These efforts had mixed results, since it was difficult to find intelligence officers who had grown up in Stalinist Russia who could fluently navigate life in the west, and the leaders of Soviet Intelligence became less able to understand this difficulty. Also the international prestige and mystique of the Soviet Union had declined, making it more difficult to recruit ideological agents thru an illegal network, which had been so successful in the 1930s and 1940s.

McCarthism's overreach did make western public opinion increasingly skeptical of the extent of Soviet intelligence efforts in the 1960s, 70s and 80s, so on balance it's difficult to say whether it hurt or hampered Soviet Intelligence in the long run.

Source: Andrew, Christopher. The Sword and The Shield - The Mitrokhin archive and the secret history of the KGB.