Regarding the registration of guns - this item may be pertinent.
Judge upholds DC gun registration requirements - Washington Times
It is regarding registration of guns in Washington DC and was very recent.
If it can be done in Washington DC, it can be done elsewhere in the USA.
The gun ownership I was talking about was for seniors over 80 years old and that an annual vision and skills test be given. If they pass it - fine. Same for driving. You cannot argue against that reasonably. I also said I do not expect it to happen so sarcasm is not necessary.