That's a great explanation of some of the benefits! These are the most important in my opinion: "You can make those from the air too. Drought? Use fusion power to run desalination plants. Arable land becomes a non-issue with fusion because vertical farming becomes easy." You could also use this water to stop desertification, which would be a great thing.

I do disagree with you on Hydrogen fuel cells replacing electric cars though. I think battery powered cars will be better than hydrogen powered ones. The power storage is more reliable, and the power transfer is more simple (lines as opposed to truck delivery or pipeline. And if we assumed that it would be done on site at stations, then they would already have power lines, so just use that!)