*Modern Egypt has been heavily influenced by Islam since the late 7th century. But what if the Arabs had not invaded and Coptic Christianity had not replaced the ancient civilisation? What might Egypt be like today? (as an Egyptologist, I've wondered about this a lot)

*There wasn't a lot left of the pharaonic culture, by the time Christianity took root in Egypt.   In fact, it is thanks to the Copts' preservation of the last evolution of the indigenous Egyptian language (completely supplanted by Arabic for everyday use) that Ancient Egyptian scripts were able to be deciphered.   Even though the Ptolemies built spectacular temples in the old Egyptian style, their Egypt was very Hellenised, with Greeks/Macedonians and Jews enjoying higher status than indigenous Egyptians (the latter weren't even supposed to live within Alexandria, for example).  Although individual Romans, such as Germanicus and Hadrian, are recorded as having taken an interest in what were already considered "Egyptian antiquities" in their day, the culture that had created the pyramids and Karnak was already long gone.   During the persecution of Christians in the time of the Emperor Diocletian and his Caesar Galerius, the Southern Temple of Amun at what is now Luxor (which appears to have been functioning as a Christian church by then) was converted into a shrine to the Tetrarchs, i.e. Diocletian, Galerius and their two Western colleagues, rather than being restored as a temple of Amun, presumably because by then no-one could remember who Amun was.

As for the copyright question, I don't think that the Egyptian authorities ever planned to go hunting in architecture and the internet for hints of Egyptian influence and demanding royalties.  I think they explicitly stated that that place in Las Vegas would not be affected, precisely because it plainly was not an exact copy (the Fourth Dynasty car park was a different shape), which tends to suggest that their interest lies in unauthorised replicas of items in the Egyptian Museum.

When is a copy not a copy?   The temples of Abu Simbel and Philae were both moved, to rescue them from the waters of the Aswan High Dam.   They use the original masonry, but they are not in the original locations, so they are not exactly copies, but they are not wholly authentic, either.