Why does the Torah see fit to record all the details of the Avos, many of which are seemingly of minor importance, such as their travels from place to place and the episodes of the wells?
Ramban: This is due to the principle cited in the Medrash Tanchuma 'Whatever happened to the Avos is a sign that it would later happen to their children'. And he (and the other commentaries) proceed to interpret them, one after the other. 1
The Ramban cites examples of prophesies that the Nevi'im preceded with a symbolical act, such as Yirmeyah, who ordered his Talmid Baruch to tie a stone on to Sefer Yirmeyah and cast it into the river - adding 'so will Bavel sink!'
What does the Torah mean when it writes that Avram 'passed in the land'?
Seforno: It means that Avraham did not stop in any one place until Hashem told him to, as Hashem had instructed him (in Pasuk 1). 1
This might also be what Rashi means when he comments that 'he entered into it'.
Why did Avraham go specifically to Shechem - seeing as he did not stay there anyway?
Ramban #2: Avraham established ownership over Shechem even before Hashem gave him the land, 3 a hint that his children (Yakov, in Parshas Vayishlach) would acquire it before the Kena'ani reached the stage that they were unworthy and had to be expelled from the land. 4 And that is why Hashem ordered Avraham to acquire the land and to do various acts that would resemble things that were destined to happen to his descendants later. 5
Moshav Zekenim: Below, Avraham said "I am childless" (I will not have heirs)! Initially, he thought that he will have children due to Tefilah. When he delayed to have children, he despaired.
This is recorded in Parshas Vayishlach.
And in Pasuk 8, the Torah describes how Avraham pitched his tent between Beis-Kel and Ai, because [Ai] this would be the first place that Yehoshua would conquer in the conquest of Kena'an [excluding Yericho, which was conquered miraculously - Rav Chevel].
'What happened to the fathers is an indication of what would later happen to the children'.
In similar vein, he explains how the Nevi'im would issue commands to their disciples or to kings to perform acts that allude to imminent historical events. As an example, he cites Yirmeyah ha'Navi, who ordered his disciple Baruch to take the Sefer that he had just written about the evils that would befall Bavel, read it, and then to tie a stone on to it and throw it into the river, adding - 'so will Bavel sink!' In fact, he explains, sometimes those acts not only indicated what the future had in store, but determined it.
Since Elon Moreh is another name for Shechem, what is the point of the repetition?
Rashi: Hashem showed him how his descendants would receive the Shevu'as ha'Torah on Har Gerizim and Har Eival. 1
In Parshas Ki Savo, where the Torah refers to Shechem as 'Elon Moreh' (Ramban).
Why was Shechem called 'Elon Moreh'?
Targum Yonasan and Rashi (in his second explanation): 'Moreh' means teaching, since that is where Yisrael accepted the oath of the Torah.
Ramban: 'Elon Moreh' means 'the plains belonging to Moreh'. 1
This is like 'Elonei Mamrei' means 'the plains belonging to Mamrei'.
What is the significance of the Pasuk "and the Kena'ani were then in the land"?
Rashi: Although the land had been given to Shem, the Kena'anim 1 were currently conquering it from them. That is why, in the following Pasuk, Hashem assures Avraham that He will return it to his children (who were the offspring of Shem). 2
Targum Yonasan and Ramban #1 3 : The Pasuk is telling us that although the land was destined to go to the offspring of Shem, the time had not yet arrived for that to happen, and in the interim, the Kena'ani were living there.
Ramban #2: Having entered Kena'an without clear instructions, Avraham was afraid of the wicked Kena'anim, which is why he did not build a Mizbe'ach; until Hashem brought him to Shechem, and promised that He would give him Eretz Kena'an. From that moment on, his fear departed and he built a Mizbe'ach and served Hashem publicly.
Moshav Zekenim: This cannot be, for Cham built Shechem for Kena'an (Sotah 34b)! Tzidon, north of Eretz Yisrael, was the north border of Kena'an! Rather, it was of Kena'an; Shem was taking it, for Kena'an was his slave. Hadar Zekenim learns from "Ki Lo Shalem Avon ha'Emori" that it belonged to Kena'an! Rather, half was of Shem, and half of Kena'an. Or, it was all of Kena'an; when he was cursed, it was [decreed that it be] taken from him when his sin is complete.
רש"י: ויעבור...נכנס לתוכה: למה לא פירש רש"י שהוא עבר את הארץ ויצא ממנה?
גור אריה: א"כ צריך היה לכתוב 'ויעבור...את הארץ' ולא "בארץ".
רש"י: שכם- להתפלל על בני יעקב: מנין שהתפלל שם?
גור אריה: אם לא כן, קשה למה עבר עד שכם דוקא?!
רש"י: אלון מורה - הוא שכם: מנין שאלון מורה הוא שכם?
גור אריה: בפסוק כתוב תחילה שהלך עד שכם, על כרחך שהם אחד.
רש"י: ששם קבלו ישראל שבועת התורה: לכאורה מספיק לספר לו שיקבלו שם את התורה, ולמה היה צריך להראות לו?
גור אריה: יש מקומות בארץ הקשורים במעלה העליונה לברכה או קללה, והקב"ה הראה לו את מעלת הארץ וכיצד הם מתקשרים לעליונים.
גור אריה: 'המקום גורם' וכשבא למקום הראוי לכך, באה אליו הנבואה על הדברים הללו.
רש"י: הולך וכובש...מזרעו של שם: מנין לדרוש כך?
גור אריה: משמעות המילה 'אז' שזה לא היה קודם לכן.