Hi! :) thank you so much for playing and for your feedback!
You’re right, currently the needs are already in place, but the facilities to satisfy them don't exist yet. I will think of a way how to make the next update less confusing but still showing that more content is coming.
Regarding the whistle: releasing the train with it can make you slightly faster, so you wll get more passengers overall, but it is not necessary to do so.
I agree, and I already have plans to add more indicators and explain the needs more clearly. :)
For the cat, I’m also considering giving it an effect radius. So when it purrs, nearby passengers may give you some bonus hearts <3