Lyle,
This is a short answer to your questions. However, I answered all of these types of challenges in the following thread – Why coercion is an essential and beneficial element of maximal-capitalist society.
the foundation of ancap society will be capitalism — not pacifism
hence if an investor, firm, or society believes that they can obtain a profit by using coercion to obtain valued resources – then coercion it is.
moreover, I have demonstrated why this is advantageous to society:
coercion is used to redirected mismanaged resources from inefficient enterprises to economically efficient enterprises.
for example, the owner of a valued resource (people, land, capital, et al) chooses to forego economic/monetary gain for some aesthetic goal. the owner foregoes drilling for oil because he values quiet walks in a pristine forest to the economic gain offered by oil drilling. Eventually, his land will be annexed by force since a economicallly motivated investor, firm, and society will judge the use of coercion profitable considering the previous owner had under utilized his resource and therefore under defended it.
if you consider it theft when a negligent owner is relieved of his property or resources and society has become more productive as a result – then theft it is.
for example, I would not consider the coercive overthrow of marxist cuba by anarcho-capitalists as theft. however, if you want to call it theft, that is your prerogative.
nonetheless, ancap society is not based on pacifism. It is based on profit.