Thank you Dr. Manish. After thinking it over, it seems to me I am confusing two different definitions of the word “choice.” The definition you, Dr. Herbener, and Mises are using, at least for this case, is that when you choose a means to satisfy a particular end, you are choosing to use that means for that end rather than using it for another end (and here it is clear to me now how scarcity follows). The definition of choice that I was thinking of, and that was confusing me, was choosing a particular means to satisfy my ends rather than another means to satisfy the same end. For example, rather than using the boards to stretch, I could stretch using some other device (to satisfy my end of stretching).
Is the second definition of choice not sufficient (absent the presence of the first definition, but with everything else we consider part of action, e.g. takes time, trying to change future state into one you prefer, etc.) to establish a purposeful action? And is it that, somehow, the board is not a means, but something else is a means?
Also, I will take note of the book sections you have outlined and read them as soon as I can.