1)
Why does it mention here Ohavav?
1.
Radak: They are better than Yir'ei Hashem (19); they love Him not for hope of good, or due to fear of punishment for their sins, rather, amidst pure love. He guards them, that affliction will not come on them. So all Yisrael will be in the future!
2.
Malbim: For those who love Hashem, He destroys and takes vengeance on their enemies. For Yir'ei Hashem (18-19), He only saves them. The level of Hashgachah is according to the level of Avodah and closeness to Hashem. Also refer to 145:19:2:1.
2)
Will He truly destroy all the Resha'im?
1.
Radak: Yes. No Rasha will remain in the world - "v'Hayu Chol Zedim v'Chol Ose Rish'ah Kash v'Lihat Osam ha'Yom ha'Ba" (Mal'achi 3:19).
