> Q1. Is the Geyser Hypothesis valid?
I'm not sure what you mean by "valid". ANY hypothesis not contradicted by evidence or experiment is "valid". Any hypothesis that agrees with experiment and its metaphysics (theory) might become theory.
I have somewhat less confidence in the hypothesis that "atum" was a geyser than that they used water to build. It is nearly "certain" that stones were pulled straight up the sides of the great pyramid but the means to do this is far less certain.
I believe my "theory" (ancient definition of theory rather than modern or synonyms for "hypothesis) has a significant probability of representing the reality used top build pyramids. ie- there is a ~70% chance that atum was a geyser who built pyramids in his name of "seker".
I will not say, and never will, that it is 100% certain that the pyramids were built with water or that stones were pulled up the side because I'm not 100% certain of anything. Certainty is about beliefs, not science and not reality. Anything you know for a fact is a belief.
> Q2. Was the GP built circa 2750 BC .
> Any failure to concisely answer these two easily
> answerable questions will confirm more hypocrisy.
I don't know. I'd wager that if we knew when they were built that there is 80% probability G1 was built between about 2850 and 2650 BC. It's may be a little more likely to miss to the more recent date than the older one. There is a 90% probability it was built between 3000 BC and 2500 BC. With as little evidence that exists at this time significantly older dates still have some chance but there's very little chance it dates to as recent as 2200 BC.
"2750 BC" is hardly the time it was begun. Rather it is the working hypothesis I use when I need a time period for construction. It appears to be the locus of all data that says when the pyramid was built. This being said it might be noted I've underweighted knowledge about pot shards and their relationship to other cultures and their implications on the age of the pyramid. If I knew more about this evidence I'd quite likely believe the pyramids were a little younger.
The bottom line is nobody knows and I'm in this group of people who don't know.
I'm guessing they built mastabas with geysers beginning around 3100 BC, the first great pyramid around 2900 BC and began the Great Pyramid not long after 2750 BC. The water failed throughout the Land of Rainbows about 2700 BC. This may well have been caused by an event and that event might have been the formation of the huge sinkhole north of the Fayuum. We need evidence and scientific testing and investigation but none of this is being done. "Scientific investigation" in this instance is the systematic search for anomalies and their study. Instead we have leaders who are afraid of the data and afraid of the pyramid. They are afraid to lose their beliefs to evidence and logic. They are afraid to risk tweaking the status quo.