"And the Holy Bible is merely an extension of the original story and plan. One and the same."
You're not suggesting that Jesus was the fullfillment of of what the wise had been saying for ages are you ? :-)
I get a bit cautious because I think the 'ancient egyptian religion' was not one religion but a mixture of completely different things, some based in cosmically deep truths, and others based in fear, vanity and even evil. Someone from the distant future or from a different planet, would not understand what christianity is about if all they had was a history of the last 2000 years. Unfortunately religion gets hijacked by people and sways with the times. When you take the immense amount of time covered by the term "ancient egypt", I rekon its good not to lump it together too much.
That said, I do think there are roots from the old testement that reach into ancient egypt, just as there are roots in christianity that reach into the old testament. The quotes from the AE you use could me matched with the many references in the old testament to christianity such as Isaiah 53.
And maybe the "mountains of the moon", the source of the nile, are both the home of the atlantis of plato and the garden of eden of the bible. The rivers flowing down from the mountains match plato's account very well as does the large flat plain. Its interesting to note that the Nile was born 12 500 years ago, what caused it to spill out from the lakes and be born is not clearly known. And anthropology puts the rift valley at the heart of the story of humankind. It would make sense for Zep Tepi to be both the "first time" and the source of the nile, what with the way the nile was so central to their whole culture. We have the likes of the ruins at Nabta ---> A stone circle in Egypt is the world's oldest astronomical observatory which suggest that the knowledge of astronomy you referenced from Josephus could have come to egypt from africa rather than europe. I'm certainly no afrocentrist but even just the fact Ptolomey knew that the source of the Nile was in the "mountains of the moon", which we didn't work out until the 19th century, is certainly something to think about. Maybe ancient egypt formed when one wave out of the rift valley met with another earlier one, one that still retained stories from their old home.
This is quite an interesting piece from here
Moon river and the mountains of the moon
There is a Chinese legend, in which a hero named Chang Ki'en reached the moon by sailing up the River Huang Ho. When he got there he met the god of love and marriage, Wu Kang and a hare
In the 5th century B.C. Herodotus visited Egypt and travelled up the Nile as far as Elephantine. On his journey, he met a priest who claimed to know where the source of the Nile was. There were apparently two mountains called Crophi and Mophi, and in the centre of each was a vast bottomless fountain. These two fountains gave rise to the Nile. Herodotus was sceptical. Ptolemy (A.D. 90 - A.D. 168)elaborated upon this story, and located the fountains in a range of mountains south of the equator, which he named "The Mountains of the Moon". Why he chose this name is not known for certain. Arab explorers in the dark ages spoke of the Mountains of Gumr. Gumr was believed to be a corruption of Kama meaning moon, but it could also be derived from kumr meaning pale green. Abu el Fadel, an Arab traveller, writing around A.D. 1098 suggested that the mountains are so called, "because the eye is dazzled by the great brightness" He goes on to explain that:
"Some have said that certain people have reached these mountains and ascended there and looked over the other side where they saw a sea with troubled waters, dark as the night. This sea being traversed by a white stream, bright as the day which enters the mountains from the north, and passes by the grave of the great Hermes, and Hermes is the prophet Idrisi.
It is said that Idrisi there built a dome. Some say that people have ascended the mountains and one of them began to laugh and clap his hands and threw himself down the other side of the mountain. The others were afraid of being seized with the same fit and so came back. It is said that those who saw it saw bright snows like white silver gleaming with light. Whoever looked at them became attracted and stuck to them until they died and this science is called human magnetism.
It is said that a certain king sent an expedition to discover the Nile sources and they reached copper mountains and when the sun rose the rays reflected were so strong they were burnt
It is said that in the days of Am Kaam, one of the kings of Egypt, Idrisi was taken up to heaven and he prophesied the coming of the flood so he remained on the other side of the equator and there built a palace on the slopes of Mount Gumr. He built it out of copper and made 85 statues of copper, the waters of the Nile flowing through the mouths of these statues and then flowing into a great lake and thence to Egypt"
The glowing stream flowing across a dark sea sounds to me like a description of the Milky Way***. Perhaps this story is allegorical, or maybe it was originally an African version of the tale of Chang Ki'en****. The story seems to have influenced "Beach house on the moon" by Jimmy Buffet
After this the Mountains of the Moon appeared on many maps, but no one was sure exactly where they were supposed to be. Alexander the Great and Julius Caesar both sent unsuccessful expeditions up the Nile. In 1858 Burton and Speke led an expedition to find the source of the Nile. They reached Lake Tanganyika, and then illness and personal differences caused them to split up, Burton remaining at camp, while Speke headed north. 16 days later Speke reached Lake Victoria, and returning, declared that he had found the source of the Nile. Burton disagreed, insisting that the source was at the Mountains of the Moon, which he suggested lay between Lake Victoria and the most southerly known part of the Nile. Speke suggested that they lay between Lake Tanganyika and Lake Victoria. Speke made a number of further expeditions, and accounts of his explorations were published in 1863 and 1864. but the dispute continued. A public debate between Burton and Speke on the subject was planned, but on the day that it was due to happen, Speke died mysteriously, shot by his own gun while hunting.
In 1885, Stanley discovered the Ruwenzori mountains close to Burton's suggested location of the Mountains of the Moon, and after that, the Ruwenzoris were The Mountains of the Moon. Whether they were the same Mountains of the Moon referred to by Herodotus, Ptolemy et al. is anyone's guess.
On Bubembe, an island in Lake Victoria, is a temple containing a stone which (legend has it) fell from heaven, and points east or west, depending on the phase of the moon. 
"She" by H. Rider-Haggard, was published in 1885, and seems to be set some way to the south of this region. The Hammer film version of the book was set in the mountains of the moon .
Osiris was said to have been born at Mount Nissa in Ethiopia, perhaps this was imagined to be "The Mountain of the Moon". Osiris' Greek counterpart, Dionysus, was born at Mount Nyse in Greece - which may be the origin of his name . There are also three Nyssas in Asia minor, three Nysias in Thrace, a Nyza near Mosul and a Nysia in Arabia. According to Diodorus, this last place was where Isis was born . Anyway what I'm getting at is that sometimes the stairway to heaven may have been imagined as a river. Perhaps Osiris, the fertility god of Egypt was sometimes imagined as a personification of the river Nile - the source of Egypt's fertility, and was thus born at the place where the source of the Nile was imagined to be. This is probably a good time to put in a link to the section about Osiris and Set.