Re: Pressure suits?
People, get your systems engineering right.
Linear acceleration could be similar to an airliner on take-off; a bit uncomfortable but nothing worse, although as someone mentioned above, it'll take a loooong distance to accelerate to top speed.
Breaches of the tube will "only" be a problem if a) they occur within the emergency stopping distance of the capsule, and b) they include a breach of the rails, or misalignment of the two broken-apart tube sections. In all other cases, it'll be an emergency stop and ticket refund; but in that combination it'll be a disaster.
Quite another topic, however, is turn radius. By my quick BOTE check, in order to keep centrifugal acceleration to an acceptable level at speeds of 1100 m/s or so, you'd need a curve radius of several hundred kilometers - the exact value depending on what you consider "acceptable". That means we're essentially talking arrow-straight tubes; which even in China would place a fantastic burden on the poor civil engineers tasked with routing the system.