A capsule is irrelevant. To get to 750mph they actually have to get a track that can mitigate all known and unknown physical problems that stop trains nowadays from even going over 350km/h during operation. Showing a mockup does nothing to address hyperloop's baseless promises and simpsons monorail reenactment. To put it in perspective, its as if they showed a supersonic jet when they didn't even recognized the existence of sonic booms.

And what happens when the train stops unexpectedly between destinations? It becomes a coffin.

That looks streamlined. I thought the idea of the hyperloop was that it was low vacuum and the front of it was a giant fan to move the remaining air from front to back of the capsule to further reduce friction. Or was that only in the early design and it's been abandoned?

That was Musk's plan. In addition, the fan powered an air beating.

Prior to release of his plans he specifically denied that it was maglev in an evacuated tube. However the name got quickly coopted by people who were building maglev in a tube.