Why did He say "Shuvu Banim"?
Malbim: Even though the fathers did not repent, I call (request) that in any case, their sons should repent.
What is the meaning of "Shovavim"?
Rashi: It is wayward. You made your way wayward amidst abundance - you had serenity and pleasure - "ha'Poretim Al Pi ha'Navel
What is the meaning of "Ba'alti Bachem"?
Rashi: I called you by My name, that I am your Master. It is not honorable for Me to leave you in the hands of My enemies.
Radak: I will be intimate with you after I divorced you.
Radak citing Targum Yonasan: I chose you.
Radak citing his father: I was repulsed with you. We explain like this because the following word begins with Beis. The same applies to "Ba'alti Vam 1 Ne'um Hashem" (31:31).
Malbim: Even though I divorced your mother with a Get, I considered you like My wife, and I am your husband.
Surely this is the correct text. (PF)
Why did He say "Echad me'Ir u'Shenayim mi'Mishpachah"?
Radak: Even if one Jew is alone in a city of Nochrim, or two in a nation, I will take him/them. A nation is called Mishpachah - "v'Im Mishpachas Mitzrayim Lo Sa'aleh" (Zecharyah 14:18), "l'Chol Mishpechos Mamlachos Tzafonah" (above, 1:15).
Radak citing Sanhedrin 111a: One person in a city can bring merit to the entire city; two in a family can bring merit to the entire family; all will leave exile due to them.
Malbim: Even if only a small number remain, I will take them in the future.