Will Hashem Himself rise against them?
Radak: No. I will arouse [others] against them to cut them off.
Malbim: Yes.
Will He cut off Bavel?
Radak #1: He will cut off Melech Bavel. Via cutting off his seed, Bavel was cut off and destroyed.
Radak #2: He will cut off the residents of Bavel. All will die via the sword - fathers and sons together.
Malbim: He will cut off Beis Nebuchadnetzar, and kingship from Bavel.
What are "Shem v'Sheir v'Nin v'Neched"?
Megilah 10b:"Shem" is the writing, "Sheir" is the language, "Nin" is the kingship, and "Neched" (grandchild) is Vashti.
Rashi: "Sheir" is She'eris (a remnant), "Nin" is a son who rules over his father's kingship (Belshatzar), and "Neched" is the grandson (Vashti).
Radak: "Shem" is anything that recalls his name. "Sheir" is a relative, like "Ish Ish El Kol Sheir Besaro" (Vayikra 18:6). "Nin" is the son, and "Neched" is the son's son. Also Targum Yonasan says so.