1)
Why does it mention seeing their affliction?
1.
Shocher Tov 1 : Yisrael will be redeemed only amidst five matters mentioned in verses 44-47 - affliction, Tefilah ("b'Sham'o Es Rinasam"), Zechus Avos ("va'Yizkor Lahem Briso"), Teshuvah ("va'Yinachem k'Rov Chasadav"), and the Ketz "Hoshi'enu Hashem Elokeinu v'Kabe'tzenu Min ha'Goyim"]. Moshe put them in one 2 verse - "ba'Tzar Lecha u'Mtza'ucha Kol ha'Devarim ha'Eleh b'Acharis ha'Yamim v'Shavta Ad Hashem Elokecha v'Shamata b'Kolo; Ki Kel Rachum Hashem Elokecha
2)
What is "Rinasam"?
1.
Shocher Tov: It is their Tefilah.