What is the connection between the birth of Yosef and Yaakov's request to take leave of Lavan?
Rashi #2 (to 35:29) and Rashbam: Yaakov decided to return home now because the second set of seven years (during which he had worked for Rachel) had terminated.
Tosfos ha'Shalem (1, citing R. Yosef Karo): As long as Rachel had no children, he feared lest Esav take her Bal Korcho (against Yaakov's will).
Tosfos ha'Shalem (5): Lavan would not let him leave before all his wives gave birth, lest he divorce a barren wife.
Kli Yakar: Rachel's Nevu'ah that she will have one more son confirmed the Siman of the 12 rocks that became one under Yaakov's head, that he would father 12 Shevatim. If so, Esav cannot kill him now (before he fathers another son from Rachel).
Ha'amek Davar: As long as Rachel had no children from Yaakov, he feared lest Lavan say that he will marry her to someone else.
Rashi: As the Pasuk writes, "And the House of Yaakov will be fire, the House of Yosef, a flame, and the House of Esav, straw" (Ovadyah 1:18). See also Targum Yonasan.
Tosfos ha'Shalem (2): Esav's sin was pursuing his brother. Yaakov's first 10 sons, who did similarly to their brother, cannot punish Esav for this. Yosef, who returned to them good in place of evil, can. (Perhaps this qualified him more than Binyamin, who never sinned - PF.) Tosfos ha'Shalem (5) - also Yehudah, who did not hate Yosef (he saved him), can punish Esav.
Why are there crowns on the Hei in "Yaldah"?
Tosfos ha'Shalem (5) #1: This hints that because Rachel did not have a Hei in her name, a Hei was added to Yosef's name - "Edus bi'Yehosef" (Tehilim 81:6).
Tosfos ha'Shalem (5) #2: Rachel was one of five barren women in Tanach [who merited children] - Sarah, Rivkah, Rachel, Mano'ach's wife and Chanah.
Why did Yaakov mention, "Mekomi ul'Artzi "?
Malbim: My parents are there, and this is my birthplace. Here I am a stranger. Had I asked to go elsewhere, you could have stopped me.
Ha'amek Davar: Had he said 'l'Artzi ul'Mekomi,' this would mean near his parents. However, he could not; surely Esav is still angry, for Rivkah did not send for Yaakov to return. Yaakov could go only l'Mekomi (his own place, away from Lavan) ul'Artzi (Eretz Yisrael), but not near his parents. She warned him not to return until she sends for him. If not, he would never have agreed to stay with Lavan for the sake of income! 1
QUESTIONS ON RASHI
Rashi writes: "When Rachel gave birth to Yosef - i.e. when the adversary of Esav was born, as in the verse, 'The house of Yaakov shall be fire (Esh), and the house of Yosef, a flame (Lehavah), and the house of Esav shall be straw ' (Ovadyah 1:18). Fire without a flame cannot exert its effect far away; once Yosef was born, Yaakov trusted in Hashem, and desired to return." Why did Yaakov need the additional power of Yosef, in order to combat Esav?
Gur Aryeh: Yaakov and Esav are diametrically- opposing forces. 1 Nevertheless, Yaakov himself could not overcome Esav, for they were carried together in the womb. At that time, Yaakov was a "partial" rather than a whole entity, which is by definition still in potential form, not yet perfected enough to exert an effect. Only when Yaakov was actualized by having children (and specifically though Yosef, his main offspring - see 37:2), would he be able to overcome Esav, for Yaakov's children would have nothing in common with Esav. This is the deeper meaning of the Chazal cited by Rashi - Yaakov was the fire, the source, and Yosef was the flame, to spread Yaakov's influence outwards.
Maharal (Chidushei Agados Vol. 3, p. 126, to Bava Basra 123b): Yosef's advantage is in the inner world, as his offspring is compared to fish, upon which Ayin ha'Ra has no power (see Rashi to 49:22). Esav is all external; "the hands are the hands of Esav" (27:22). Therefore, specifically Yosef's power is able to defeat Esav. 2