This makes me wonder: Is there a machine where a machinist could make
one part "by hand", i.e., in the normal way you'd use a regular mill
or whatever, but where the machine could record the machinist's actions,
and then "play them back" for the next part? Or is it only possible to
drive an NC by writing a string of textual commands?

My control has a "teach" mode to record points but you still eidt to
make a program. I never used one but the bridegeport protrack was
supposed to do this.

Karl