There certainly aren't any good articles countering assumption #1.  The only explicitly pro-Soviet propaganda films from Hollywood were made during WWII, largely at the behest of the government, when (in case conservatives have forgotten) the Soviets were our allies in the European war.  Plenty of movies in the late '40s/early '50s dealt with themes of naming/not naming your friends/associates, taking a dive for the mob, etc., which were obviously influenced by the blacklist.  Which, as conservatives also conveniently forget, damaged the careers of plenty of movie people who had never actually been Communists (unlike the "Hollywood Ten," all of whom had been party members at some point).

Also easily forgotten is the fact that being a Communist wasn't illegal, in and of itself, and that what the Hollywood Ten went to jail for was contempt of Congress, since they refused to answer any of the questions they were asked.  As bad as apologizing for Stalin was, the only case available to conservatives nowadays is that that particular political belief (naive and/or odious as it was) warranted expulsion from the movie business.  The NY theater business didn't blacklist anyone, so perhaps conservatives can try to make the case about how that threatened US national security (this was one of the things that Elia Kazan's critics latched on to, the fact that he had such great success in theater meant that he didn't have to rely on movies to make a living, so he wouldn't have been out of work if he had been blacklisted, unlike many of the career-long movie people who had to go to Europe to keep working).    

You could make the case that Dalton Trumbo's screenplay for Spartacus is fairly commie-friendly and contains some coded swipes at American hegemony, but it's a stretch.
I'm far more alarmed by the apparent fact that if the IMDB bio of the NRO writer is correct, then it takes twelve writers to produce According To Jim.

I would like to challenge what everybody knows to be true, but isn't. Being an American Communist in the early days is nothing to be ashamed of and everything to be proud of. "Put in as much as you are able, take only what you need," is a very high ideal. Against that noble sentiment America could offer only, "Grab as much as you can for yourself and if everyone else starves, that's their tough."

The liberals of the twenties and thirties should not be tarred for wanting to believe the Communist ideal could work. If some of them clung to the Soviets' perversion of it longer than they should have, misplaced idealism is their only fault.

Amidst the mass murders and subjugations of whole populations, did Soviet Communism do any good? Absolutely. Without America's fear of war torn Europe embracing Communism there would never have been a Marshall Plan. Without pressure from a system that (theoretically) treated workers as human beings, Capitalism would never have reformed itself as much as it did.

We have not heard the last of Communism. Add God to "Godless Communism" and you have the Christian monestaries---the community of Jesus and the disciples. The right wingers who so fear Communism must be reading an alternative Bible, where Jesus told his followers to invest in property. Communism is not to be feared, we simply aren't ready for it yet.  

Kazan and Steinbeck made "Viva Zapata" in 1952. It was an anti-Communist film, but it would be regarded as a populist leftist film today. In those days you could be pretty far left and be centrist.

Maybe I'm interpreting the writer too charitably, but his question seems to be more along the lines of developing a debating rebuttal, independent of what he actually believes. He's identified assumptions that form the underpinnings of one argument and is looking for evidence to counter them.

It's true that an uninformed person cannot reasonably "believe" that some assumptions are wrong, but they can believe that the were insufficiently supported and could conceivably be refuted.

The fact that some conservatives consider it important to try to defend McCarthyism this long after the fact strikes me as a greater pathology than a tendency to form hunches and "fix evidence" around them.