Why is He called "Elokei Yisrael" here?
Malbim: Yechezkel saw the revelation of His honor due to being Elokei Yisrael. This name alludes to His connection with Yisrael and His Hashgachah Pratis that clings to them, to conduct them miraculously. I.e. he saw that His Shechinah will return on them and raise a banner for those who fear Him.
From where did the honor come?
Radak: It entered the gate via the east. Malbim citing Mahari ? the east alludes to his power and ability, due to the eastward motion of the daily Galgal (sphere) that moves all Heavenly bodies from east to west, the opposite of their own motion from west to east. Chazal said, if not for the noise of the Galgal of the sun, the clamor of the city (Romi) would be heard (Yuma 20b). Kol ha'Galgal silences the clamor of the city that denies Hashem' existence, like Akeidas Yitzchak wrote.
What is "v'Kolo"?
Radak: It is the sound of His honor.
Radak citing Targum Yonasan: The voice of [angels] blessing His name.
Malbim: His Hashgachah will be revealed to all.
What is the significance of "k'Kol Mayim Rabim"?
Radak: This is like at the beginning of the Sefer, just there it adds "k'Kol Shakai" (1:24). It is the sound of His honor.
Malbim: This is all 'water' of existence that makes heard that "Adir ba'Marom Hashem" (Tehilim 93:4).
What is the grammatical form of "He'irah"?
Radak: It is Po'el Omed (the action applies only to the subject; the land itself illuminated). Other verbs from this root are Po'el Yotzei (one illuminates another), e.g. "He'irah Verakav Tevel" (Tehilim 97:4), "Leha'ir Al ha'Aretz" (Bereishis 1:15).
What is the significance of the land illuminating?
Malbim: The eye will see revelation of honor of His Shechinah, and Nevi'im see His honor.