The best way to improve things with minimal suffering is to only hold the most powerful people accountable. You’d force them to redistribute their power and ensure people everyone is happy. If they refused to do their best, only they would actually suffer, not their soldiers or subjects that had no choice in how things are run.

You’d discourage people killing in your name, telling them that you’ll do it yourself. This would basically mean that you have a monopoly on violence, as even violence that would normally be justified couldn’t be if you might do something about it. You’d need to have impossible knowledge on all things, or you might get tricked or mislead by someone into doing harm yourself.

You’d become the state, encouraging or forcing people to do the right thing. It would make society better if you have good intentions and divine wisdom, but many would hate you for taking their freedom for reasons they struggle to understand. I wouldn’t hate you, but I’d always question you and never love you. We’d be at your mercy, hoping that you never change for the worse. We’d never know for sure that you would always be good.

Alternatively: Just don’t create life capable of free will in the first place and save yourself a huge headache.