1)
Will this be soon after the Navi said so?
1.
Radak: No, it will be long after. It will be the day of Yisrael's redemption. Since Hashem said that it will be, it should be considered close.
2)
Why are there two expressions - "Ka'asher Asisa Ye'aseh Lach" and "Gemulcha Yashuv b'Roshecha"?
1.
Malbim: There is punishment for (a) the deeds themselves, and (b) the hatred and envy amidst which they were done.