1)
Why does it say that Hashem made a Satan for Shlomo?
1.
Rashi (23): Hashem told David "I will be like a father [to your son]; when he transgresses, I will afflict him with the staff of people?" Malbim - "and My Chesed will not depart from him? your house and kingship is faithful forever" (Shmuel II, 7:12-16). Hashem afflicted Shlomo for his sin until he regretted his deeds, and there was a remnant for David's seed and a Shevet remained for his son's kingship.
2)
When did this occur?
1.
Radak: It was in his old age.
3)
What is the meaning of "Hu be'Edom"?
1.
Radak #1, Malbim: [Seed of] the king in Edom.
2.
Radak #2: Hadad was in Edom.
