Who says "Ki Ani Yadati"?
Radak: The author. I command you to praise Him, for I know His wonders and deeds.
Malbim: It is a Yisrael. He says, I do not need wonders to clarify that Hashem is great. I know it from His creation and conduct (refer to 135:6:1:2).
Why does it say "Adoneinu"?
Radak: We accepted Him to be Master and Elokim over us. The other nations accepted the Heavenly legions for their Elokim, each according to its custom.
Malbim: This refers to Hashgachah.
What is "Gadol mi'Kol Elohim"?
Radak: It is greater than the Heavenly legions and the angels that conduct the world; therefore, they are called Elohim. Our Master is greater, for they act only with His power and command.
Malbim: He is the first and last cause of everything. He conducts, oversees and rules as He wants. All natural forces submit to His desire and Hashgachah.