Don't know the answer to question 2 although I suspect that the answer is no.
Questions 1 and 3:
1. Don't think so as AC Reg failure is normally pretty self-destructive. Moreover, light smoke output even at the high setting is relative to which model you are considering and what its EFX settings are as well as the smoke fluid volume.
2. Clockwise BUT certain Lionel Legacy smoke units are wired to run in the opposite direction because of the air channel in the specific smoke unit. I get impatient with this every time I find it because every Lionel (or MTH) smoke impeller I have seen is designed to spin clockwise.