What do we learn from "El he'Harim Lo Achal"?
Rashi citing Targum Yonasan: On the mountains he did not serve idolatry, to eat offerings to dead [gods]. Radak - they used to offer sacrifices on mountains, like it says 1 , and eat them there. "El" is like Al; the same applies to many verses.
I.e. "Avdu Sham ha'Goyim... Eloheihem Al he'Harim" (Devarim 12:2). (PF)
What is the praise "v'Einav Lo Nasa..."?
Radak: It goes without saying that he did not serve idolatry - rather, he did not even lift his eyes towards it - "Al Tifnu El ha'Elilim" (Vayikra 19:4).
What are "Gilulei"?
Rashi: They are other idolatries, e.g. Ba'al in Shomron, and [Yaravam's] calves in Beis Kel and Dan.
Why does it mention Eshes Re'ehu [and Nidah]?
Sanhedrin 81a: He did not adopt his colleague's profession (in a way forbidden due to taking away his business).
Radak: After mentioning idolatry, which is Bein Adam la'Makom and is equal to all the Aveiros, it mentions Aveiros Bein Adam l'Chavero, e.g. Arayos that man is close to [transgressing] them. It need not mention relatives, for most people refrain from them, even Resha'im.