1)
Why did he say "Ani Mofeschem"?
1.
Malbim: All the actions that I did, so will be done to them. Yechezkel's three exiles are a sign of their exiles ? two that passed, and the third will be in the days of Tzidkiyah.
2)
Why does it say "Ken Ye'aseh Lahem"?
1.
Radak: It does not say Ken Ya'asu Lahem, for they were forcibly exiled.
3)
What is the significance of "va'Shevi Yelechu"?
1.
Radak: There is Galus that is not Shevi, e.g. "v'Gam Goleh Atah li'Mkomecha" (Shmuel II, 15:19) and "va'Yaglum El Manachas" (Divrei ha'Yamim I, 8:6). Malbim ? Shevi is harsher than Galus. It is on condition not to return from the land to which he is taken.