I have only seen the one. All of your safety concerns except fire were covered. They really don't mention to much about station design, but does mention the pod withstanding pressurization and depressurization.

As far as size for wheel chairs it mentions having a pod that could fit a car(a Tesla of course) so fitting a wheel chair shouldn't be much of a challenge, or for the smaller pod it mentions being over 6 feet tall and over four feet wide I don't see why you couldn't fit a wheel chair in that amount of space.