If I was supreme leader, I don't think I would mess with retirement ages or the age where you gain certain rights.
That stuff is always going to be messy.
The late RBG was once asked, if she could amend the constitution, what amendment would she put?
She said, "I'd make it easier for you to amend the constitution."
A very wise answer.
I would do the same if you gave me a chance. Take, for instance, Roe v. Wade. Various states had decided by their own democratic processes, including more than 40 years of votes from women, that intentionally ending a pregnancy was a criminal offense. But the US supreme Court held that the US Constitution gave people the right to end a first trimester pregnancy if they wanted to. At the time, abortion was only legal in one or two states. But the supreme Court decided they had the authority to change the laws in more than 40 States overnight. I don't have a problem with that per se, but I don't think the supreme Court's decision should have been the final word.
I would amend the Constitution to put hedges around the supreme Court's power. For instance, my amendment would say that if they write a decision like Roe that cancels a state or local law, that decision should be put on hold for a few months to give the US Senate a chance to respond. Remember, the Senate is supposed to represent the interests of the state governments. If say 60 senators agree that the state law is constitutional and should stand, then it should stand, and things should go on as if the ruling never happened.
Then, maybe once every 10 years, a special committee would be appointed, including former presidents and retired judges, to consider all the times that the Senate and the supreme Court disagreed, and propose constitutional amendments to clarify things. They would send those amendments out to the states for ratification. Right now we have no regular way to start the process of amending the Constitution.
If we had a process like this from the beginning, constitutional law would probably make a lot more sense. As it stands now, the two words "due process" in the fifth amendment have three distinct meanings, last time I counted. It was just a team of nine people, mostly from the East coast, who dreamed of these meanings over decades of decisions, filling in all the vague parts of the Constitution with books full of specificity, and they did not have to consult with anybody. They should have had to consult with the legislators, and it should have happened at regular intervals.

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