What are the ramifications of "va'Yistom"?
Torah Temimah: It is like an acronym for 'Sonei, Nokeim v'Noter' (hates, takes revenge and bears a grudge). The Nochri festival 'Satarnura, 1 is based on Temunah (hidden) hatred - 'Sonei, Nokeim v'Noter' (Yerushalmi Avodah Zarah, 1:2). In Rome, they call it 'Santura de'Esav.'
Alei Tamar (1:2): In Defus Vilna, it is Saturnalia. This is an acronym of Sinah Temunah Nokeim v'Noter; the Lamed (in Saturnalia) is in place of a Nun; they are interchangeable.
Why did Esav opt to wait until Yitzchak died before taking revenge from Yaakov? Why didn't he kill him immediately?
Rashi #2 (to Yechezkel 35:10): Esav went to Yishmael to marry his daughter, having in mind to incite him to kill Yitzchak 3 (in order to inherit his father Avraham). Then he (Esav) would avenge his father's blood and kill Yishmael - and end up inheriting both Yitzchak and Yishmael. 4
Ramban #2: He was afraid that his father would react by cursing him.
Targum Yonasan: To avoid the mistake that Kayin made, by killing Hevel while Adam was still alive, (with the result that the latter had another son). He would be cleverer, by waiting for Yitzchak to die before killing Yaakov, rendering him Yitzchak's sole heir.
R. Ashereli: Yaakov learned constantly; Esav knew that he cannot kill him while he is learning. He thought that during the Aveilus over Yitzchak, when almost all Torah is forbidden, Yaakov will cease a bit, and then he can kill him.
Oznayim la'Torah: He was embarrassed to kill his brother without a just excuse - and afraid that the Beis-Din of Shem and Ever would sentence him to death for murder. (Therefore, he would wait until Yitzchak dies; Yaakov will claim a double portion, for he bought the Bechorah, and they would quarrel, and he would kill him).
Malbim: He did not intend to wait! He intended to kill Yaakov, and bring close the days of his father's Aveilus over Yaakov's death. 5
Ha'amek Davar #1: His Mazal will be bad during Aveilus (so it will be easier to kill him). Esav's Mazal will not be bad; he does not follow the Torah, and has no Aveilus.
Ha'amek Davar #2: Esav realized that Yaakov will go away. [He said, 'he will return when Yitzchak dies, and during the Aveilus we will be together and I can kill him'].
Ha'amek Davar #3: During Aveilus we will be together in brotherhood, and he will not guard himself from me.
Chochmah u'Musar (Vol. 2, p. 425): How was he able to hold back his anger? He recognized the greatness of his father. His intellect did not allow him to act against [Yitzchak's] will. Intellect works even for a Rasha like Esav, and all the more so for Yisrael!
Lev Eliyahu (Bereishis, p. 174): Even though Esav excelled at Kibud Av, and did not want to pain him, he wanted his father to die, in order to kill Yaakov. The heart of a Rasha rules over him!
Which is what he meant by "Let the days of mourning of my father draw near."
His plans fell through however, because Yishmael died at that stage, as Rashi explains at the end of the Parshah (Refer to 28:9:3:1).
I find this difficult. If so, it should say 'Akriv' (active), and not 'Yikrevu' (passive). Also, it should say 'Ki Aharog'! Also, why was Rivkah concerned lest both of them die the same day? (Perhaps she misunderstood his words. However, this is unlike Rashi (to 27:42), who says that she knew his intent through Ru'ach ha'Kodesh! - PF)
If Esav loved his father, how could he say, "Yikrevu Yemei Evel Avi"?
Oznayim la'Torah: It seems that his hatred of Yaakov was more powerful than his love towards his father!
Bearing in mind that Esav harbored thoughts of murdering Yaakov, why did he refer to him as "Achi"?
Oznayim la'Torah: Because he planned to use his father's death and the subsequent inheritance, of which Yaakov would claim a double portion, as an excuse to fight with Yaakov and kill him - just as Kayin killed Hevel as a result of the argument over the inheritance.
Ha'amek Davar: Refer to 27:41:2:10.
Regarding Esav, it says "he said in his heart." Regarding David, why does it say "he said to his heart"?
Ohr Yechezkel (Midos, p. 322): A Rasha's heart guides him and rules over his intellect. A Tzadik is always in war; he makes his intellect rule over all forces of evil. Chochmah u'Musar (Vol. 2, p. 327) - Chazal could have explained "b'Libo" like "El Libo." They understood that there is a Diyuk (teaching that one must rule over his heart).
Why did he say, "let come soon the days of Aveilus...", and not explicitly, 'let my father die soon...'?
Ohr ha'Chayim: Aveilus begins after sealing the coffin. The Mes knows what is happening until then (Esav did not want to pain his father even after death). 1
Why does it say "Al ha'Berachah Asher Berecho Aviv"?
Malbim #1: He also hated 1 his father for affirming the Berachah to Yaakov.
Malbim #2: He also hated 2 his father for the Berachah to himself, "Es Achicha Ta'avod."