The verb "cut off" applies to each of these phrases, but has been used only once to avoid repetition. Alternate translation: "I will cut off every remnant ... I will cut off the names of the idolatrous people among the priests" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
Destroying is spoken of as if it were cutting something off from what it was a part of. See how you translated this in [Zephaniah 1:3](./03.md). Alternate translation: "destroy" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "cut off ... the names" is an idiom that means to cause people to forget them. Alternate translation: "cause everyone ... to forget the priests who are idolatrous" (See: [[rc://en/ta/man/translate/figs-idiom]])