Earlier quoted context omitted.
If mutation is the engine of evolution, an increase in mutation should mean an increase in the speed of evolution. Obviously not on the scales we're talking about here, but the premise doesn't seem too unsound, external pressures being equal.
Mutations can be beneficial, benign, or harmful. Smoking obviously only really creates the latter two.
That's definitely not obvious. I would agree that mutations due to smoking could be in majority harmful due to the chemical components and the high temperatures involved. Other than that, a mutation is a mutation, whether due to smoke, nuclear irradiation, high altitude, or chance. In all cases, they can be beneficial or harmful. The evolution process will then cause only the beneficial ones to perdure.