Oh bloody hell. Where to start?
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I'll take an easy one for now.
I've quoted from a petrographer in my last message who says 'We're not close to accepting even as a remote possibility a man-made origin of the pyramids."
Dude, read the article properly. Don't just scan it and assume it says what you want it to say.
That quote is referring to the theory that the stones in the pyramids were cast using an unorthodox formulation of concrete, rather than being carved from solid bedrock. The petrographer is saying that the mainstream opinion is that the stones were indeed quarried in one piece rather than being cast. So, the stones themeselves were not man-made (ie: concrete) but natural (ie: quarried).
As has been pointed out already, most of the pyramid is either limestone or sandstone. These were chosen because they are soft and easy to work. The accuracy of the builders is impressive but not superhuman. There is a lot of mythology getting around regrading the accuracy. It is far from what could be achieved using modern methods. Modern surveying methods tell us that the pyramid is about a foot out of square, has sides differing in length, and a base that is a bit out of level. If it was built by aliens that had advanced technology their surveyors must have been drunk on the job.
ETA: Oh, and pyramids are simple. They're just a collection of tapering block walls wth a bit of batter and a fancy cladding.
Also, your claim that 8,000 tons of granite is "a lot": do the math. It's actually not that much in terms of volume. In rough terms you're looking at a block about 25 metres long, 10 metres wide and 10 metres high. It's bigger than a house brick but not exactly humungous for a large building project, and only some surfaces needed to be accurately finished. The other surfaces could be left rough. The blocks were intially split out of the quarry via a laborious method that relied on splitting the rock rather than actually digging it out.