Sorry for the delay in replying, I was hunting down an old thread for you, regarding point # 2.
It’s my post in a thread specifically about digital/biometric safeties and similar options on firearms. I’d suggest looking into the whole thread, but I’ll copy-paste a couple of paragraphs about the current issues regarding the implementation of such things.
Are costs prohibitive? Yes, but that’s a so far . The iP1 mentioned in @Strassia’s post (great info BTW) is no longer for sale, but when it was available, ran @ $1600 -1800 (!!!) for the paired gun and watch, and was only .22 LR. Which is over 4x the cost of a normal, well made .22 Semi-auto. Prices for the next generations have not been released, and at least one is planned in the common 9mm, but prices will have to come down a lot to be seen as not burdensome.
On a note as to if it actually works… kinda/sorta. One, this is a RFID style device, so it pairs over short range to keep the pistol activated. According to the articles, people were able use a jammer to prevent it’s operation with parts costing around $20. My research into the biometric options have come up with zero prototypes, but at least one aftermarket option that was a $400 add-on and only worked on 1911 frames. Mechanically, the only test I found mentioning the iP1 found it to have substantial Failures to Fire (which were likely mechanical and could be smoothed out if it had ever made it to major production) and slowness in pairing.
So it’s an area that could absolutely use more research, both in reducing costs (which is/was burdensome as it stands) and increasing reliability. It is possibly (probably even) a good long-term fix, but isn’t nearly there yet sadly. And since there was only a single example I found of any sort of aftermarket biometric option for existing firearms, it doesn’t address the tens of millions of pre-existing firearms that would need to be bought back by the government or otherwise addressed to make sure the change was nationwide.
It could be done (please read the thread) but I don’t think it will be done due to the financial and political costs involved. If the technology matured (which is a hope), I could definitely see myself arguing for legislation that all future sales of new guns have the tech, but still don’t think we could get a consensus on applying this fix to existing weapons.