My comments on your suggestions:
1. make it illegal at the state level to use public money and public officials to run PRIVATE political party elections. This would force open elections for everything from dog catcher to president. Right now the political parties set the rules, and the process leaves out the ever growing number of registered voters.
There's a whole school of political science thought that having some public money to candidates is a good thing for democracy, making them less dependent on the people who supply the money. In the USA, the more important elections are the primaries, not the general elections. I can't see either private or public money improving these elections.
2. A good idea I have seen is ranked voting.
I agree that it would be better. But the 12 limitations of western democracy are totally in place. Ranked voting is also criticized for being too complicated, disenfranchising some voters.
3. Find a way to do away with gerrymandering.
I agree. But my TDG has a much better way to deal with that: grouping people into neighborhoods of about 200 people.
4. Have enough states that total 270 electoral votes pass the law requiring the electors to vote for the popular vote winner.
Sigh. Another revisionist of the electoral college, which was a tool of the founding fathers for an indirect election of the president, but was turned to a direct election. Ms. Clinton got 65m votes in 2016; Mr. Trump got 62m votes; He got most of them on his own merit; he was a viable contender for the job in 2016; stop blaming the EC. The EC will never vault a non-contender into the job.
5. Promote the idea to the electorate that if they vote only for those who take small donors only, then these new politicians just might work for the people instead of the oligarchs.
Big money will always find a way to get more than its fair share of influence. The TDG takes that influence out entirely because elected representatives are not dependent on any money to get their job.
6. I am sure there is something I am forgetting.
Yes, the US Constitution was created circa 1800, with men who were racist, misogynists, and elitists. In all other fields, we have discarded archaic models of understanding, and moved on to better models. Keeping the US Constitution is like saying the only smart people the USA were alive in 1800. Since then, . . . . .