You state that the Emhotep value for QCN "was an average slope for the whole of the shaft, including the west-pointing portion". This is not very helpful - to reach the intended line of the shafts from the chamber walls the short sections of the westward-bending part vary all over the place, obviously to circumvent the Gallery. (IVth dynasty egyptians were remarkably 'orthogonal' in their work). The angle of the long straight part(s) of the shafts is what we after. The short horizontal sections of the four shafts all differ in length - they intercept the lines of the shafts. More probably the sloping lengths of the shafts were related to a virtual origin (as in KC south).
Then you say - "for QCN's geometric model I would guess that the overall slope is 3:4, and if QCN sports a set of marks 7 cubits below its blocking slab (which has not been penetrated) similar to the marks found found near the end of the QCS shaft, then I would guess that the model the theorized QCN marks convey is a 3:4:5 triangle with specific dimensions 66-88-110".
But the slope of this shaft is definitely nowhere near the slope of the hypoteneuse of a 345 triangle, even allowing that Emhotep's figures are vague. Anyway you say "I would leave the QC shafts out of it" - sage advice considering the confusing data. You know if someone with standing could approach Emhotep or Djedi we might perhaps receive the data we need. Some academics have been quite accomodating. Edwards, Strudwick, and the late Glen Dash to whom I remain extremely grateful for help with Giza measures.
The shaft correlation to stars, even if vague, gives meaning to the pyramid. The mythology of heaven is quite explicit in egyptian work. In Khufu this was expressed in severe abstract form, using the language of geometry and time (astronomy) to provide order - or MAAT. Elsewhere it was represented in iconographic form. Here is a coffin lid with NUT above and the stars of north and south beside her -
So I think there is a correlation with the shafts. As for the pyramid correlation it is less certain - Menkaure is too small. This does not rule out the Orion correlation but, for those of us who argue for a multigenerational plan, it cannot represent the chief design consideration.