Any system of gun safety that requires the user to be within a specific range of a transmitter in order for the weapon to function is a non-starter. A radio signal can be jammed, it can be traced/tracked and fail completely making the weapon a paper weight or club when it is most needed.
If these weapon safety systems become mandatory, the first thing a criminal will get is a jammer that blocks the arming portion of the system. Next will be the police/government. We would be effectively disarming the public.
No can do.

I say make them, and sell them, like anything else. Try to force them on us? You might as well go ahead with out in the open gun confiscation; there is no difference. I would never, ever, buy any of this technology. Never.
For child security, I would recommend a Drag-n-Draw Gunsafe. They can keep their GPS and RFID to themselves.