(5) ...If one makes a mistake and prays [the Amidah ] of the week on Shabbbat, and he doesn't remember it's Shabbat [until after] he moves his feet (i.e. completes the Amidah), he must return and start from the beginning. [However,] if he does not move his feet, even though he has completed his prayer (i.e. finished reciting all of the words but hasn't yet moved his feet to complete the Amidah), he only goes back [to the paragraph in which the day] of Shabbat [is sanctified]. (And if the leader of the service forgets it's Shabbat during Shaharit, see Siman 126).
What are the most important parts of the Amidah according to this text? Why?
What are the most important parts of the service, according to this text? Why?
What is your takeaway from these sources on how to amend the service?