1)
In Divrei ha'Yamim I, 22:9, Hashem said "Shlomo Yihyeh Shmo." Why did He call him Yedidyah?
1.
Radak: "Va'Yishlach" refers to the previous verse. [David] called him Shlomo, for so Hashem told Nasan to tell David. We find that the prefix is in place of 'because' - "Atah Katzafta v'Necheta" (Yeshayah 84:4) is like Atah Katzafta Ba'avur Ki Chatanu. David called him Yedidyah, for the Navi told him that Hashem loves him.
2.
Malbim: Hashem gave to him an additional name due to His love for him.
2)
Why does it say "Ba'avur Hashem"?
1.
Rashi: Because Hashem loved him.
