Thank you for your valued insights into the historical aspects of this film's connection with ancient Egypt. I must say, I have never heard these points brought up before regarding "Charlie Chan in Egypt"!
Admittedly, I know very little of the things and customs of ancient Egypt, but, if I may, I will offer this feeble "explanation" of the seeming errors that you point out:
Perhaps the high priest, Ahmeti, was something of an egomaniac that thought of himself as at least an equal to the Pharaoh. As he possibly had something of a hold on the Pharaoh (maybe he feared him, due to his very close association with Sekhmet), who, for some unknown reason, allowed this apparent blasphemy, Ahmeti believed that he had the right to enclose his name inside of the cartouche normally reserved for pharaohs. He felt, then, that the god Osiris would welcome him to the land of the dead. Maybe he also thought that by having the goddess Sekhmet as something of a guide or ambassador has, so to speak, he could be even more assured of a warm reception from Osiris upon his arrival in the land of the deceased. Thus, the goddess was placed in his tomb with him.
Had he lived, Professor Arnold, who was certainly researching the very inconsistencies you note, would have attempted to uncover the answer to that mystery, as well! Over the decades since the opening of Ahmeti's tomb, archeologists have examined the work and discoveries of Professor Arnold, and still have not fully explained fully the mysteries that you have presented here in this humble forum...
