1)
Why does it say "Einai Al Kol Darcheihem"?
1.
Radak: It is unlike they say "Hashem does not see us" (Yechezkel 8:12).
2.
Malbim: I look both at the ways of the Nefesh and the Midos from which the sins sprout, and on the sins themselves, which are the evil deeds - "Po'al Adam Yeshalem Lo uch'Orach Ish Yamtzi'enu" (Iyov 34:11). Examples of Darchei ha'Nefesh are cruelty, pride, and vengeance, which depend on [My] knowledge. Therefore it says "they were not hidden from Me". This is unlike human judgment, which looks only at the deed.
2)
Why does it say "Lo Nitzpan Avonam mi'Neged Einai"?
1.
Malbim: This refers to the deeds, which are visible.
