I see you've posted this in RKBA as BillH has suggested but these straw men are so easy to knock down I just can't pass it up.
As to point one which is the same straw man rephrased three ways. One simple answer: remove all semi auto guns with removeable magazines from circulation. I just said ALL. The only reason the police have these weapons is that civilians had them first. The fact that all these 'law abiding citizens' were out gunning the police is why the .38 service revolver was retired. The police have them because the gunners started an arms race that finally resulted in the police having MRAPs for fucks sake.
As to point two, address point one and it's a moot point.
Point three is a regurgitation of point two and it is also moot once point one is addressed.
About the fear of red flag laws being used against you, if you're such a dick to your family that they use red flag against you then you probably are a menace to yourself or others. In the event it really is unjustified there are laws against filing false reports to a judge. It's covered, okay?
Caches of hidden guns are everywhere and if/when some idiot gets himself on the radar for an action serious enough to warrant confiscation they won't do much good from a jail cell. I read about such caches being found after an arrest all the time so it's just more gunner bull shit. It's also a logical fallacy to argue in the extreme and not worthy of rebuttal.
So, there ya' have it. I just set fire to the straw men your imagined.