Hey, Goose.
You are right on the first one - "Incidence" here is the Angle of Attack, which is sometimes referred to as "Aerodynamic Incidenece", mostly in the older English publications. These days they have taken to calling it Angle of Attack, just like in the US. The angle between the longitudinal axis and the chord line is the good old Angle of Incidence now, just like you said, so no worries there.
Not sure about the second question - I haven't come across anything like that in training either. My guess is that it must be some kind of procedure from the old days, when they utilized the actual aircraft a lot more for crew training, and such speed - the crew training Mmo - was published. Also, it could only apply to some particular type of an older jet, Davies makes a lot of disclamers like that throughout the book.
Hope it helps.
Spektor.
P.S. When is the Interview? Mine is July 1st, NYC.