I don't really believe anything here - I'm just talking about principles that are defined. Pretty much exactly your issues with anarcho communism also apply to anarcho capitalism in that there really isn't any way to enforce private property boundaries and related phenomena associated to private ownership of the means of production other than either a government or a private equivalent to government (which would basically just be a government).
In reality, the point I make over and over in anarchy groups online is that pretty much no 'sub genre' of anarchism can live up to real anarchy very easily without pretty radical shifts in the hearts and minds of the people involved. As far as I'm concerned, if there is a ruler then there is no anarchy, period. If we haven't experienced such a state then we don't really know it's benefits.
If anarcho communists want to initiate purges and governmental control then they aren't anarchists, period.