To give more realism to the railway world, I would personally put crew NPCs, who perform the same functions as in real life, such as when the train arrives at the station, they get off the platform welcoming the passengers and once everyone is inside they perform the action of closing the doors.
If regular NPCs don't function correctly, (often walking onto tracks, not getting off train at terminals, being on ecs moves) I don't think NPCs with actual functions should be a priority. Having said that, with actual scripted tasks to follow, maybe they'll work better. Also, why is the paragraph in bold and italics?
Great idea!!! I think it would be good, they can ensure the trains are empty before they leave the station, stop members of the public from stepping off the platform onto the track. Stop passengers from going vertical up into the air, dropping down through footbridges, sinking into the platforms, guide passengers to platforms that trains actually stop at...just saying but yes, there is a lot to fix first with the passengers NPCs, but yes station staff would be nice. Maybe even passengers at Euston station.