One Final Fantasy world I would not want to live in, would be the Final Fantasy Crystal Chronicles-because this game takes place in a world that is covered in poisonous gas called Miasma. These peple are living in settlements around large crystals which keeps the mist off and protects the people from danger.
I think FF7 universe is very intriguing. I'd love to be in universe where cloud, sephiroth and genesis are alive. It'd be interesting to see how the world can be in that. It was fun playing the game. I loved that and sequels of that universe.
With Sephiroth looking to destroy the planet in FF 7 with the view of achieving his mother's dream, plus it's an industrial planet that pollution have affected so bad, I don't think it's conducive.
I prefer staying in the world of FF 9.
I think that I would go with your choice of universe one would like to live in the Final Fantasy game. The planet in FF 7 does not look so good, there are lots of damaged structures which poses as a threat to life and survival.
This is completely true, even though I enjoyed what happened in FF 7 but the planet doesn't look so good to live in at all.