On your first point, I meant to say that it would ban them for those under 21. To suggest that a legal adult who can be drafted into or volunteer for the army should not have the right to a freaking Ruger 10/22, which is probably the most popular rimfire rifle in the US by sales, is a little overboard. It's not exactly the choice of mass shooters by any stretch, and nor would it be effective for them.
To your second point,
So, yes, in some cases, they can. Whether it is successful or not could be up in the air, as they do have what on the surface appears to be a decently designed law. But they may also get into a situation where the evidence is the professional opinion of the person who initiated the whole thing, which can easily allow for personal biases.
However, this article throws up a few red flags, yet conveniently doesn’t really delve into the data behind them.
While we all agree that people should exercise their civil rights responsibly, attempting to strip someone of them for that reason seems a bit orwellian. What other civil rights should we be allowed to strip from others because we don't think they are exercising them responsibly?
So their implementation seems to be a bit racist, with black people being almost twice as likely as white people in some jurisdictions to be stripped of their rights.
This is also concerning. The article lists possible reasons, such as individuals not having proper representation to make them stick, but the fact that a group of people who have proven themselves to be untrustworthy time and time again has such a disproportionate success rate should raise some questions.
So that thing you claim doesn't happen actually does happen. I'll give you the benefit of the doubt and assume you mean that it isn't successful. And that's fair. But how many of those frivilous cases have been pursued by the law to enforce penalties on those false accusers? I'm guessing the number is something close to the number of cases that are pursued against people living on their form 4473. Which is close to zero. I would like to see some statistics on that if anybody can find them.
There is plenty of evidence out there that these laws have the potential to be abused, and gun owners can have a legitimate concern about it. This is why I suggested the model I suggested. It allows for the law to be tailored to meet those suggestions and gain more trust from gun owners and develop a system that everybody except the most fringe elements can work with. The alternative is to keep saying there is nothing to worry about while nothing ever happens.