Why did chariots and horsemen (cavalry) accompany Yosef to bury Ya'akov?
Ramban (49:31): Because he foresaw that Eisav would cause trouble.
Seforno: Because they considered Ya'akov a warrior.
Even though he had had no reason to display his fighting skills during his stay in Egypt. The Seforno and the Ramban argue over whether the Egyptians accompanied Yosef of their own accord
Why does the Torah write here "Vaya'al Imo ... ", and on the return journey, "ve'Chol ha'Olim Ito'?
Oznayim la'Torah: Because on the way to the burial, they were all of one accord
Refer to Bamidbar, with reference to the difference between "Im" and "Es".