I hate it when a photo has conflicting levels. I had one recently where if I levelled the photo based on getting the vertical parts vertical, the background looked disconcertingly tilted, but if I straightened the horizon, the verticals looked all wrong, and no amount of
lens distortion correction would fix it, in the end I discarded the photo in frustration and put it down to it being an error in my
composition of the shot. The mountain range wasn't level, but with no other ground reference, the brain tried to make that the horizon, so the mind complained if it wasn't level, but that tilted all the buildings vertical lines, and the brain complained about that too.
I think you answer your own question with the reference to the quote about making anything skewed look very deliberate. A couple of degrees people will put down to badly taking the shot and want it straight, whereas if you deliberately took a shot of someone at 45 degrees, you'd be making it pretty clear it was for artistic or emphasis reasons, and that would be much less likely to trouble the viewer, but it may still not be as aesthetic to people as a level
composition of the same subject.