Usual great puzzle on a Sunday.
Bit of incidental information is turned over with pleasure (9) = SIDELIGHT
is turned over = SI, pleasure = DELIGHT
Lack of faith he’s shown in source of notes (7) = ATHEISM
he’s = HES, source of notes= ATM
Popular Conservative policy that’s not on the level (7) = INCLINE
popular = IN, Conservative = C, policy = LINE
SIDELIGHT = Bit of incidental information; Any incidental illustration