I believe Champollion and others said that without his knowledge of Coptic he wouldn't have been able to decipher anything.
"What else can you interpret from the depiction of a mummified form? "
Well I might fall back on Apache tradition :
This reflecting and experienced warrior told me that the reason why they buried all the worldly goods of dead people with their bodies, was because of a strange disease which broke out among them several years before he was born, and carried off great numbers. It was found that to use the clothing or household property of the deceased, or to come in contact with such person, was almost certain to result in a like sickness to the individual doing these things,
To contain a disease ? Did they have a funeral industry that exploited grief for profit by promoting embalming? Did they think it sanitary?
"Feathers have always weighed less than human hearts so we can safely assume that we can not interpret the image literally."
The scene you describe is symbolic, and one would automatically look for explanation in the text surrounding the scene. When the text is, to say the least, ambiguous, it is most audacious to fill in the blanks. It could have a purely medical meaning. Maybe they did autopsies.
"Think of the last funeral you attended:"
Would this be a white, modern, english speaking funeral? You imply that funeral prayers are an innate, inherent practice that, by their nature, would span all cultures and so what we do NOW, would also apply to ancient cultures. The AE's were not english speaking white people drowning in Christian beliefs.
Suppose I am an Apache indian circa 1800. Would you be as certain as to how I address the spirits of the trees, buffaloes, etc ? Or maybe I am an Australian aboriginal; would you venture to guess what my funeral would entail ?
Of course not. Yet Egyptology has projected it's white modern catholic based behavior onto an ancient culture. It is this exact behavior that was the demise of the American Indian.
"I have no more 'proof' that a pharaoh had various honorific titles than your own speculation that they did not."
Let's see if I understand correctly. There is no 'proof' that a pharaoh had various honorific titles, and there is no proof that they did not. Then it is, at best, a guess and has no business being touted as fact. But I would wager that egyptology will persist in it's insistence that it is fact.
But all this is beside the point. My point is that eygptologists have changed letters, inserted words, left out words, and flatly assumed definitions. And these antics have given us, in many instances, a completely false definition of crucial words such as Khufu, Sothis, Sphinx, Apis, Harmachis, King, RA, etc. If the definitions are false, the conclusions that follow are false. The definitions should be thrown out because they were established using a faulty methodology.