Regarding ground changes, we can look to current bullet-train rail systems. Nobody has ever died on a bullet train in Japan due to earthquakes. I saw on a documentary that Japan feed seismic sensor data into train control centers where any dangerous seismic event would trigger automatic stopping of the trains.
No passenger has ever died on the Japanese Shinkansen, but a train was derailed during an earthquake. The safety of high-speed trains, both in Japan and elsewhere, also relies on safety during a derailment by keeping the train rigid and having steel cars. In contrast, it seems to me that a breach of the integrity of the hyperloop tube would probably be fatal. Also, the higher speed of a hyperloop makes automatic stopping take longer.
In all, the hyperloop as it's currently being presented is much more dangerous than high-speed rail during an earthquake, and this is a legitimate concern.
