suggestions for corrections 

Hi,
I'm not a native english speaker, so I hesitate to edit some mistakes myself:

Whether the sarcophagus was ever intended to house a body is unknown. It is too short to accommodate a medium height individual without the bending of the knees, a technique not practiced in Egyptian burial, and no lid was ever found.

I never heard about the sarcophagus being too short, this is certainly not generally accepted knowledge.
Also, there are many other presumed items missing, such as the portcullis blocks (alleged remnants are left), some kind of slide connecting gallery and ascending passage, entrance blocks and the entire floor of the queens chamber. Keep in mind that the pyramid was open for centuries with no guards whatsoever-only immovable or almost immovable structures remained until the first attempts to a professional description of the interior more than 3000 years after construction.

Egyptologists suggest the chamber was intended to be the original burial chamber, but that King Khufu later changed his mind and wanted it to be higher up in the pyramid.

The 'change in plans'-theory has been suggested by some, but AFAIK is rejected by contemporary egyptologists such as Lehner and Stadelmann. Instead, they suggest an intended unfinishedness for religious purposes.

The Greeks believed that slave labour was used but modern Egyptologists accept that it was built by many tens of thousands of skilled workers.

Not "the Greeks", but Herodot writes about slaves, a myth which seem to be ineradicable. He visited the pyramids 2000 years after the construction and beside naming the builders correctly, had not much of a clue about anything else.

The Great Pyramid is the only pyramid known to contain both ascending and descending passages.

I'd say the satellite pyramid of the bent pyramid counts, too. It has a remarkable similarity to the great gallery as well. Minor point, I know.

The National Geographic Society filmed the drilling of a small hole in the southern door, only to find another larger door behind it.

I know Hawass said that during the show, but no other egyptologist believes that. Look at the images yourself. There have been no further attempts made to "open" the alleged door. I'd say, don't call it a second door until proven otherwise. The shafts seem to end in this tiny room-a very similar structure can be found in the southern upper shafts as well, by the way.

Joyce Tyldesley states that the Great Pyramid itself "is known to have been opened and emptied by the Middle Kingdom"

I wonder where Mr. Tyldesley got that information from. I am not aware of any ancient source regarding the opening of the pyramid. While I believe it has happened, and during the first intermediate period, there is nothing but vague hints in old egyptian sources-I think the term "known" is exaggerated. Herodot and Diodor claim to have been inside-that points to the pyramid being open around 450 bc, but at which point the opening happened remains uncertain. 

Hope this is helpful!
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