Suicide: by train isn't uncommon, but if they have to delay one line, there are similar lines people can use to route around the area (usually, and to great discomfort).
People on the track: I have only seen this once, aside from workers and they know the schedules and have watchers to make sure the lines are clear.
Morons not moving: pretty hard Todo that with the sheer mass of bodies moving out ;) also there is a system everyone adopts, on the outside everyone lines up in two lines outside the carriage doors, and let's the train empty, before attempting to get in.
Its quite amazing how well it works.