Why does it say "Es Chukecha"?
Malbim: Via understanding the Mishpatim well, he will guard the Chukim very much. Even though he does not know the reason, from his understanding of Mishpatim, he knows that there is knowledge and understanding also in Chukim - "Asher Yishme'un Es ha'Chukim... Am Chacham v'Navon; ... Asher Lo Chukim u'Mishpatim" (Devarim 4:6, 8). Also they have sage reasons!
Why does it say "Al Ta'azveni"?
Radak: Rather, help me to guard them.
Radak citing his father: Do not abandon me until I guard them very much.
Ma'alos ha'Torah (DH v'Chen Matzinu): I must guard Your Chukim, even if You would abandon me.
Malbim: Do not cease your influence of Ru'ach ha'Kodesh.
What is the meaning of "Ad Me'od"?
Radak: This refers to "Eshmor", like it said above (4) "Lishmor Me'od." I.e. my intent and desire is to guard Your Chukim very much, with all my heart and strength.
Refer to 119:8:2:2.
