1)
Why does the Torah not mention 'Chayim' regarding Yitzchak's years, like it does for Avraham and Yaakov?
1.
Ohr ha'Chayim #1: Before the Akeidah he did not have a Zivug, and one without a wife is without life (Koheles Rabah 9:9), and after the Akeidah his eyes began to weaken (and a blind person is like a Mes).
2.
Ohr ha'Chayim #2: He did not bring with him life until the Akeidah. (Be'er Mayim Chayim to Bereishis 22:20, from the Ari Zal - He was born with a female aspect, and could live only 37 years. At the Akeidah his Neshamah left, and he was given a new, male Neshamah.)