I think the pyramids are much older than most " experts " think !
I went to Egypt last summer and seen the pyramids in person the base looked like quadrilateral, or any polygon shape.
Nice, I'm envious, I would like to climb to the tops of all 3 pyramids !
I wish we would have did that to lol the pyramids was beautiful we visited the earliest one in Saqqara. 
Cool, some say the blocks of stone used to build them were poured ??
On the tour we learned they was built from Dimension stone which was natural stone.
The Sphinx also looks much older than 5000bc, the weathering and erosion might make it 10,000bc ??
You are right the research says that they have  rejected the water erosion hypothesis and the idea of an older Sphinx.
lol, well "they" might be biased, and looks to me whoever did the construction had high tech that we now seen to have no knowledge about.
Yes the use high technology now those products was advanced and added in the 21st entury.