4.) Working on that right now, should be in the next update.
5.) This would be easy to do on my end but I think it would complicate things a bit too much (for example when online leaderboards are added you'd have 3 separate leaderboards). I think currently there aren't enough easy and medium difficulty levels to make the difficulty curve nice and smooth. I also think I need to redesign a couple of levels to make them less awkward.
6.) This will come with the steam version in 1-2 months.
7.) I'll try to think of a way to communicate this better.
8.) This is just how the game has to work due to the grid nature of the roads unfortunately.
Thanks for the feedback, always appreciated!