Cold fusion has a 100% chance of realization. It's a sound technology. There's no doubt that it will be realized and is achievable. The only doubts are the timescale -- those who work in the field often say it's always '30 years away', but some recent research seems promising to make it much closer than that. I'd say level 5 and cold fusion are both equally achievable, though level 5 automobiles may be airborne -- as then they'd have less obstacles just birds, trees, and other airborne vehicles, but pedestrians, cats, dogs, bicycles would be off the table.

Super AI's I think are achievable and will be developed. I just don't know which will come first level 5 or cold fusion that's a toss up. If everything though has sensors including bikes, pedestrians, cross-walks, roads, etc that can detect what is on the road, send out a warning signal to cars travelling towards that intersection then that also takes out some of the problems - but that requires a very smart grid.

On a long enough timeline though there's probably not much humankind can create. Though it could be 10 years could be 50.