How were they Bnei Bayis?
Koheles Zuta 2:8: The slaves are Batei Dinim in Chutz la'Aretz. Bnei Bayis is Ru'ach ha'Kodesh.
Rav Sadya Gaon: They were dear friends and [like] family to me.
Ibn Ezra: They were born in my house.
Metzudas David: They are appointed over needs of the house, to oversee what is needed. They did not work like [regular] slaves.
What does "Tzon" encompass?
Ibn Ezra: It includes sheep and goats - "Mishchu u'Kchu Lachem Tzon 1 " (Shemos 12:21).
Above (12:5) it explained "Min ha'Kevasim u'Min ha'Izim" (PF).
Who is included in "mi'Kol she'Hayu Lefanai"?
Rashbam: All who were before me [in Yerushalayim], before I was born.