Manual access is a concern, but from what I can tell the vehicles are powered by induction instead of batteries. The cargo might be the bigger fire risk.
They really aren't. It's already known that there's a distance and throughpot threshold where roadway and railway make more sense. The main blocker on the ralway side is that infrastructure costs are quite high, and roadway's flexibility always involves trucks handling the last mile.
> Taken off so far
Other than the Beijing airport train there is no real other maglev running. Even the Virgin Hyperloop has achieved more than this project. And let's not get into what happened to them recently...