1, The staircase seems much more steeper than those new buses,
would it be much more dangerous to passengers with compare to the origional design?
I don't think that it is wise to make it "staight".
2, The modification for people to escape seems not very useful as seldom tourists are good at sport climb.
3, The exhaust pipe may save pedestrians from a "burst" of black smoke, but may cause someone to get burnt.