Nah, there's a reason why we don't talk about Stonehenge in the same ways.
There is 25 years of research at that site. You have a selection of geoarchaeological surveys to choose from... These are just a few. That site is a hot bed for extensive palaeo work.
It's cheaper to do bullshit than the right thing.
https://en.wikipedia.org/wiki/Egyptian_pyramid_construction_techniques
In addition to the many unresolved arguments about the construction techniques, there have been disagreements as to the kind of workforce used. The Greeks, many years after the event, believed that the pyramids were built by slave labour. Archaeologists now believe that the Great Pyramid of Giza (at least) was built by tens of thousands of skilled workers who camped near the pyramids and worked for a salary or as a form of tax payment (levy) until the construction was completed, pointing to workers' cemeteries discovered in 1990.[1] For the Middle Kingdom pyramid of Amenemhat II, there is evidence from the annal stone of the king that foreigners from Canaan were employed.[2]
That's a common myth. :) People didn't have to enslave each other to do magnificent things, we should take note.
You can date rock like that with luminescene dating... My dude, it's great to wonder about the past. It's a beautiful thing but this guy isn't who you should be fixating on.
I blame Quetzalcōātl, obviously.
That's a good one. :)
A borehole survey is pretty empirical, my dude. It's basic geoarchaeology and used heavily in geoscience and engineering. Most responsibile construction projects use them and you know they're not spending money on things that aren't tried and true. It is how I hunt extinct rivers and other watercourses in other parts of the world. They don't just go poof. Plus the palaeo record would show what lived in and around it.
Archaeology works backwards from the known to the unknown. We bring our own biases to science, so that's why we have to build our case for theories brick by brick, to avoid those and check ourselves. He's welcome to provide proof, but so far he hasn't had any that fits the data. We welcome these ideas when there's proof. Rivers with the ability to carve rock like that leave large footprints. Multiple people's careers would be made if there was such evidence, but there isn't. Large discoveries are good for archaeology and bring funding. Science with a capital S isn't perfect, but the data disproves it, if anything.
Some people really want to believe, and why not? It is human not to want to be alone. It's a terrifying prospect. :)