Yeah, I could add a passenger counter as a new optional tutorial!
Do you mean being able to use the cab controls with mouse? Many of the switches do not work because they are not useful yet. For example, there's no rain so you don't need to use the wipers.
There's no other warning for the speed limits except the minimap. Modern railways often have a warning sign by the track or a safety device, but 1960s UK apparently didn't. The drivers probably just had to memorise the limits.