Although a Utopian society is a great concept, it would never work without doing things that we, as humans, would probably never do. Ever read The Giver? That's a Utopian society, yet there's no colour, happiness, love, etc. Nobody is sad, but nobody knows what sadness or happiness is, so what's the point? You can't be happy without also, at some point, being sad, and vice versa. Sorta like the superhero "no-go-without-evil" thing.
That being said, if wishing for a better way for countries and groups to solve conflicts wouldn't cause huge problems, (But that would be a pretty hard thing for any genie to come up with.) I would probably do that. War isn't a happy thought, and although some groups don't care for their lives and simply want to fight for their cause, it shouldn't have to be focused on the worst aspects of life: hatred, fear, and sorrow.
Also, isn't wishing for more wishes what gets your wish destroyed or something? I think I heard that somewhere.