1)
What it the significance of the fact that Yisrael's first stop was "Sukos"?
2.
Nefesh Shimshon (on Sukos): Sukos is where Yisrael dwelt after they were saved [here, from the slavery in Egypt]. 3
2
As implied in the word "Sukos" - See Peirush Yonasan. Indeed, that is why we sit in Sukos according to R. Eliezer.
3
S'fas Emes (Devarim le'Sukos 651, citing the Zohar): After Ya'akov was saved from Eisav, he went to Sukos, because after Rosh Hashanah and Yom Kipur, the Satan chases Yisrael, and Sukos is the protection.