OK, then. I guess I'm still a little confused. This is from the first link you provided.
The "Plot Point"--According to Field, the three acts are separated by two plot points. A plot point, often called a reversal, is an event that thrusts the plot in a new direction, leading into a new act of the screenplay. Later screenplay gurus have built on Field's theory by stating that Plot Point #1, which leads into Act II, is the moment when the hero takes on the problem.
It seems not to differentiate between a plot point and an act break.
As for exactly when the first act of Star Wars
breaks, I think I can agree with what you said. However, I'd like to point out that what you said and what I had said to begin with are within minutes of each other. In defense of what I said, had Luke not found his Aunt and Uncle dead, he might not have made the decision to become a Jedi, and his dialog had indicated he might not have.
Thanks for the feedback so far.