Vayeitzei 5779

Rashi comments that it says Vayetzei to emphasize that a tzadik's exit makes an impression. Why didn't Rashi make this comment at the beginning of Lech Lecha?

To receive prophecy, once can either have a dream while sleeping or be overtaken by sleep in order to receive prophecy. If Hashem promised to be with him, why is he unsure (אם יהיה אלקים עמדי)? Why, as indicated by his dream, is he treated as if he's already outside Israel?

Why (according to the Gemara) does Leah compare Reuven to Esav. Why does the Gemara provide a reason for calling him Reuven - Leah herself already gave the reason?