You are confusing several aspects of Marxism, particularly with respect to the State. The State, for Marx, is an element of class oppression. In a classless society, the "State" doesn't exist, when property is fully collectivized there cease to be classes. What remains is a "state" in the modern linguistic sense, but for Marxists is just "government" or "the administration of things," as Engels puts it. From Socialism: Utopian and Scientific:

When ultimately it becomes the real representative of the whole of society, it renders itself superfluous. As soon as there is no social class to be held in subjection any longer, as soon as class domination and the struggle for individual existence based on the anarchy of production existing up to now are eliminated together with the collisions and excesses arising from them, there is nothing more to repress, nothing necessitating a special repressive force, a state. The first act in which the state really comes forward as the representative of the whole of society -- the taking possession of the means of production in the name of society -- is at the same time its last independent act as a state. The interference of the state power in social relations becomes superfluous in one sphere after another, and then dies away of itself. The government of persons is replaced by the administration of things and the direction of the processes of production. The state is not "abolished", it withers away. It is by this that one must evaluate the phrase "a free people's state" with respect both to its temporary agitational justification and to its ultimate scientific inadequacy, and it is by this that we must also evaluate the demand of the so-called anarchists that the state should be abolished overnight.

Marxism is not Anarchistic, it advocates for a world Socialist republic of full Central Planning and Worker Ownership, complete with hierarchy for planning and whatnot. The "state" isn't a separate thing from the workers, but the workers themselves. The concept of a State is important for the lower stage, when Private Property still exists. From Principles of Communism:

Question 17 : Will it be possible to abolish private property at one stroke?

Answer : No, no more than the existing productive forces can at one stroke be multiplied to the extent necessary for the creation of a communal society. Hence, the proletarian revolution, which in all probability is approaching, will be able gradually to transform existing society and abolish private property only when the necessary means of production have been created in sufficient quantity.

As per Stalin, I don't "defend" him, and don't appreciate your assertions that I do. I again want you to read "Tankies" by Roderic Day. Moreover, your confused understanding of Marx can be alleviated by reading my reading list.