1)
In what way will Hashem be a father to Shlomo?
1.
Radak (Shmuel II, 7:14): I will rebuke him for his sin like a father rebukes his son, and I will not remove my Chesed from him, like I did to Sha'ul and removed his kingship from him. Rather, the kingship will be to his descendants forever. [All] this refers to David's descendants, not only from Shlomo, rather, also from Rechav'am and his descendants.
2.
Malbim (here and Shmuel II, 7:14): He oversees him, and when the son begins to make his path crooked, immediately he rebukes him and returns him to the good path. He does not allow him to falter so that his Emunah will depart. Malchus Beis David is founded on Emunah and Chesed.
