Between the red flag and domestic violence part, a whole bunch of crazy women will have a field day.
Hell hath no fury as a woman scorned.
"Domestic Violence" is a useful pretext for confiscation. There are plenty of others in the new "laws".
In practice, we can be certain that anybody who owns guns and publicly criticizes the Government will be targeted for the "Red Flag" orders. The complainants are anonymous, and complaints can be filed by just about anyone. Appeals will be extremely expensive with very poor odds of success.
The "Karens" in your neighborhood will sign up in droves for the informant program.
Try to pin red flag on a black person you will get arrested for a hate crime.
Lots of potential for serious abuse of rights there.