Finally . . .
"Could this clash with the theory that the AE's orientated themselves with our North as South and vice versa? Would this affect whether the AE's would portray the image of a person (Osiris) on to the Nile and the delta in a certain way, and the placement of the pyramid?"
It could, but this design could be earlier than the ancient Egyptian concept of up meaning south and down meaning north.
There is this extract from the 'Kore Kosmou' . . . also known as "The Virgin of the World" - said to be the earliest of the esoteric Hermetic texts:
"The inhabited earth is like a human being lying face up, at the south is its head, its feet at the north; on the right to the east are fighters, on the left to the west men fight with the left hand, those to the north excel in legs and feet".
Also, do the pyramids of Khafre and Menkaure show the same design traits as the pyramid of Khufu in terms of the relevance of Osiris' head being the outline for the design?"
As far as I know, No they don't.