I caught this the other day and wanted to add in something as the quote you used is quite interesting.
I ended up coming to the conclusion that the Winter Sun was depicted in the intersection of the descending and ascending passages of G1 when it is one hour before sunrise, just as the glow of the Sun begins on the horizon. At sunrise, the Sun is depicted above the first girdle stones within the ascending passage.
My interpretation has the Sun referenced a number of times within the pyramid, and an importance placed upon the direction of entry into the pyramid: southwards, beneath ground, towards a reference to the Underworld with a pathway to the Overworld and its connection to Ourworld.
In saying this, it is because of the realms the King has to visit during the course of ritual, merging the 3 levels of existence in one construction.
And it is because of the stated, "...the king...confined in the mountain...for the prescribed length of time, and then liberated to the jubilation of the gathered crowds."
that I do not think the rituals of the pyramid were only performed on a dead body. The main reasons for this are the extensive wear upon the top step of the gallery, and 3 solar barques buried beside the pyramid.
Anyway, just some thoughts on an unproven theory, like the thoughts of many in the same boat.
And good to read you again.