What are "Orchos Hashem"?
Radak: They are the ways He commanded in His Torah, to go in them. They are "Chesed ve'Emes"; there is nothing crooked in them.
Malbim: Even though sometimes Hashem does not go on the main path, and goes on a particular path that separates from the general path, e.g. Tzadik v'Ra Lo, Rasha v'Tov Lo, also those paths are Chesed ve'Emes. Sometimes it is Chesed - the Tzadik's hardships come to atone for a small sin, or to increase his reward in the world to come. Sometimes due to Emes and Midas ha'Din, He is patient with a Rasha until his measure is full, and He makes him lose the world to come.
Who are "Notzei Briso v'Edosav"?
Radak: They are not those who distort the truth, so one cannot recognize the truth. "Ki Yesharim Darchei Hashem Tzadikim Yelchu Vam u'Fosh'im Yikashlu Vam" (Hoshe'a 14:10).
Radak citing Moreh ha'Nevuchim 3:12-13: They are those who guard the nature of existence and the Torah's Mitzvos. They knew the purpose, Chesed and Emes in everything. They engaged in essential bodily needs, but not in excesses.
Malbim: They are those who know that also Hashem's particular paths, off the general path, are Chesed ve'Emes (refer to 25:10:1:2).
