Except the passenger point I totally agree.
In my game, large hilly map on easy, to find into the game, My long range lines (4 Cities connected, from about the middle of the lane to the map edge, the train becomes full over time from station to station and the huge bunch of passangers exits the train on the final destination in the middle of the map.
I can’t imagine, that passenger behaviour changes that drastically from easy to medium.
The devs alrdy announced, that some of the points, you all brought up here, are alrdy planned to be fixed, one of them the ability to build roads over tracks.