All of these proposals are excellent in theory, but there has to be a reliable mechanism for enforcement, and serious criminal prosecutions for tricksters attempting to vote when they don't meet qualifications or attempt to vote at more than one voting precinct, etc. Also, serious police presence at the polling places is necessary as a deterrent to cheats.
Citizenship requirements have to be enforced at the time of registration with registrants required to present either a US birth certificate or naturalization papers.
You make no proposals for absentee ballots, which have been used quite frequently in (local) fraud schemes.
All this will cost state and local governments more money, but will be worth the added expense in improved public confidence in the integrity of the electoral process.
My proposal was not intended as a comprehensive list but rather serve as a starting point for conversation. And you raise and excellent point. Voter fraud should be a very serious crime. I would even support loss of voting rights and permanent prohibition against serving in any capacity at the state or federal government level.