It's an end around on Constitutional protections. If one thinks weapon ownership shouldn't be a right, then change that. This method is no better than anti-abortion tricks.
Not really. Your abortion clinic example really doesn't work.
The clinic is going to have to have buildings insurance, otherwise they would suffer a massive loss if the building was damaged beyond repair.
An insurer is going to look at the potential loss and the risk.
I've no doubt abortion clinics have very high premiums and probably have many countermeasures (secure entrances; remote letter boxes; screens over windows; fire suppression systems) to try to keep those premiums affordable.
No they don't have a government mandated insured amount, because for the most part they are insuring property which is easily valued.
But guns and cars have an impact upon people and people sue.
So long as no third party can come into contact with your gun or car then insurance is going to be superfluous and if still required will likely be a nominal sum, just to keep the paperwork in order.
But if you could cause death or injury through your ownership of a gun or a car then you could be sued to cover the costs to a third party. The amount of cover you hold should reflect the possible settlement you might make, otherwise you risk losing every asset you own or if you own nothing then the third party cannot be compensated. That's not fair on them, so insurance is a practical alternative to you losing everything and them failing to pay their medical bills.
Weapons are a right in the US, so long as you (or someone) can afford them and afford to take responsibility for them.
And as I was trying to get across earlier, the rights bestowed by the 2A do not apply in certain circumstances (mental health, criminal record, age etc etc) so it's already not a universal right; weapons aren't handed out free of charge (along with the ammo) by the government to the entire populace regardless of age, mental health or criminal record.
Weapons are allowed if you meet certain criteria and can afford them.