1)
Who is included in "Beis Levi"?
1.
Rashi: Kohanim and Leviyim.
2)
Why are there separate families of Kehunah and kingship?
1.
Rashi: It is to return their crowns to them, like it says above "Eleh Shnei Vnei ha'Yitzhar ha'Omedim Al Adon Kol ha'Aretz" (4:14).
3)
What is "Mishpachas ha'Shim'i"?
1.
Rashi: The family of Shim'i ben David. First it gave the Klal of families of Beis David, and afterwards it details each by itself.