I appreciate your even handed approach here.
In response to the rebuttal of the first objection you see levied against AnCapism. Really at the end of the day, AnComs don't want to prevent anybody from organizing themselves in whatever way suits them. We just want to be free to organize ourselves according to our principles. All anarchists desire a society based on free association.
The thing that I think most AnComs have an intuitive understanding of, and a sensitivity to when interpreting history, is that capitalism and property is never content to respect boundaries. Capitalism relies on the accumulation of capital, which demands constant growth. History has many instances of societies being built on anarchist principles only to be violently crushed by outside forces... It's a very real fear that AnComs have, that any attempt to enact our principles will be overtaken by capitalists as long as those ideas thrive.
I understand this point and appreciate you making it. I think the issue lies here in how we define "Capitalism." For me it just means the freedom to buy, sell, and trade, full stop. We can surely agree that the violence-based nation state is the real problem.