My observations.
- The Mayan calendar does not "stop abruptly", no calendar does. Rather it follows a cycle that repeats itself every 5,000 years or so for what is referred here as the "long count" and then it resets to 0. Moreover, the completion of a cycle was an event to be celebrated, not feared.
- What you refer cryptically as solar activity, are sunspots; which creates in the worst case scenarios troubled satellite communications, interference with electronics and can in some instances destabilize power-grids. (All events the Mayans would not fear of course, or care about)
No fire and brimstones apocalypse.
They also contribute in creating beautiful Aureole Borealis which are natural blessings.
- Your numerological speculations aren't Christian.
- Mayans knew the future ? Where do you get this bizarre notion ?! And then adding that this knowledge was imparted by the Devil ? I leave it to your conscience to evaluate how close you are to middle-ages ignorant populaces calling for witchcraft where it was not.
This whole new-age speculation on the Mayans and their calendar is little more then a good subject to write (and sell) books on.
To those honestly interested in the rich history, culture and civilization of Mayans and Aztecs, this site is a good point of reference:
Foundation for the Advancement of Mesoamerican Studies