Ok, let me go by your points.

1) the study of it is a disciplinee, an academic religion.
Religion - the belief in and worship of a supernatural controlling power, especially a personal God or gods. Many people are actually believing in a superior being, which religion exploits.
Marxism is a politico economic theory that deals with the distribution of surplus between the production owner and the production producer. In its political aspect, Marxism called for a proletarian revolution in all the countries in the World at the same time, and until appropriate such conditions didn’t occur, the revolution wouldn’t have to be started.
The only person who was, to a degree, an implementer of the true Marxist ideology, was Leo Trotsky. Neither Lenin nor Stalin follow true Marxism teaching. Lenin and Stalin came up with the concept of an immediate revolution in a single country.
Also, unlike religion, which congregates many true believers in a superior being, except for first 10 to 15 years on the Soviet history, people didn’t believe in it; neither in concept nor in its implementation.
So on those important points Marxism is not equated to a religion.
As for the study of it is a discipline I would partially agree with you. It was an obligatory discipline in a Soviet Higher education institution. However, the attitude toward it was not like to a religion, but rather like to political correctness in the United States. Here you also cannot say publically certain things that that everybody say in their homes. In addition, Marxism is studied not only in “Communist” countries, but also in capitalist counties as well. I know that because the units associated with Marxism were credited to me when I applied to USCD. And in America, or for that matter in any capitalistic country, your statement about “studying of it is a discipline” doesn’t apply at all.
2) Nowhere has it worked
It never worked on the scale of a country, because it was never implemented on the scale of a country. As I stated above, what Lenin and Stalin did in Russia and Mao in China, had little to do with the teaching of Marx. However, as I said in my previous response, Marxist economic model did work in 19 century in small communities and in the 20th century worked in Kibbutz in Israel.
3) Where people have tried to fit it in place to make it work the facts of the economic modes of production and their natural order of progression disagrees with the theory. I.e. the throw-off of feudalism in the United States by revolution prior to the expulsion of slavery in the United States. 1) Revolt against feudalism July 4th, 1776, removal of slavery 1865 (They occurred in the wrong order making the theory completely incorrect and it occurred prior to the invention of the theory)
Marx made his model on the sample of Europe, where things worked in the way he described in his theory. In Europe that’s how events have progressed. In America, people who revolted against Feudalism in 1776 were already freed from slavery earlier in Europe. The fact of slave trading in America only shows that evolution doesn’t involve the entire population of the World, but goes forward in bursts.
1. I think - Marxist revolution in Russia occurred with simultaneous modes of production in place feudalism, and ancient slavery (i.e. serfdom at the same time) So there was no progression only evolution, change.

Here you are completely inaccurate. The slaves in Russian were freed in 1861 a year earlier than they were freed in the United States. So by the time when the Russian revolution started in 1917 Russia had no slavery and had capitalism/ It wasn’t as developed as it was in the United States at the time, but it was there anyhow. In fact, the main support for Communists came from proletariat or working class not peasants, who Lenin considered unreliable because of their land ownership.
2. As my sovietologist professor said, "Never become a Marxist Revolutionary, once the revolution occurs they kill all of those because they are never satisfied - true (Stalinist purges).
Again, as I explained above, Stalin was never a Marxist. All the Marx’s contribution was to delegate his head on the Red banner.
So, when a theory cannot be tested by hypothesis and repeatable experiments, the theory cannot be proven and anyone who accepts it, accepts it only as a belief system. There is no real basis to accept it other than on belief that someone told you the theory was true.
When a theory cannot be tested this doesn’t mean it is not true. It just means it hasn’t been tested. However, even if it is not true, that doesn’t make a theory a religion.
Since, it is outside the known sphere of God, the alternative is pagan and so hence, pagan religion based on nothing.
Incidentally pagan religions are not outside sphere of God, but only outside of the sphere of a unique God. So again, Marxism has very little to do with religion. I would say It has one necessary condition, but has no sufficient conditions to be called a religion.