I believe the first thing Jesus would do if He rules the world today is to close down all borders and barriers of countries. There will be no United States, Malaysia, China or even Israel but only one, Kingdom of God. So, no one will go and kill another for the sake of his or her nation. Only a city will be there, Jerusalem, the city of peace where Jesus reigns.
Secondly, I believe all peoples will be taught a language that will bind them together for common good. Race or tribal issues will be wiped out. The most important identity you have will be your name and your attitude towards God and mankind.
Thirdly, Jesus would appoint judges to rule for Him without injustice, impartiality and no bribery at all. Absolute fairness. Wrong is wrong, right is right and don't even think of an excuse or blame someone for misquoting you. No more politicians. Aren't you glad? I don't know how Jesus would punish offenders. (Remember the words of Incredible Hulk...Don't make me angry....)
There will be many more things that Jesus would do. Everyone will have enough food to eat, water to drink and fuel to travel. No one will be left behind in the Kingdom of God. If you get bullied, just call, "Jesus" and help will be right away. The strong would be willing to help the weak and the rich help the poor. You just walk in the street anytime and will feel safe.
PS: Jesus is coming soon!