Mazy cat does rub her face, marking, all over the place, but it's her cheeks she's rubbing, not the ruff around her neck. Her ruff has gotten so thick!
However, she does a lot of rolling and spinning, which could twist the fur on her back, like you suggest, and that may be just that one spot on her spine she cat quite reach any more. It has that weird flakiness too, which she has no where else.
A few flakes this morning, but not twisted or rough fur.