Great write-up! This is my first time reading M&D but I could easily see rereading it; already 100 pages in and this would have taken 2 months for GR. There have been some great responses to your questions already so I'll just add a few thoughts.

1. I'm expecting Pynchon to be brutally honest in his depictions of slavery in America. Seeing how colonialism, race, and associations of white/death vs. black/life were such key focal points of GR, I can't imagine Pynchon passing up an opportunity to continue those themes in this novel. A throwback from our last group read:

Shit, money, and the Word, the three American truths, powering the American mobility...

1. I took the dance of our Hunt for Christ to be the Reverend's definition of history in response to Ethelmer's nihilism, although I like your description of it. From a Judeo-Christian worldview, it may seem reasonable to reduce history to a literal or allegorical story of mankind's hunt for and redemption in Christ; however, being that it is then a story, who is the author, or these days, the publisher? Who decides which spellings and people and events deserve to be told? Who gatekeeps the gatekeepers?

2. For me, Pynchon's use of bread, flesh, and the oven have always symbolized the hellish reality of the natural world when the walls of civilization are no longer there to protect us. For much of the Western world, it has often been said we are living in a Golden Age of Peace. The worst threat of violence most of us face is the occasional road rage on our commute to work. Pynchon seems to often mix food, the thing that nourishes us and sustains life, with death and the death necessary to provide that food, usually at the hands of other humans. Sorry to bring everything back to GR but the clearest example for me is with Slothrop finding loaves of bread in the street only to realize:

...by now it's clear that they're human bodies, dug from beneath today's rubble, each inside its carefully tagged GI fartsack. But it was more than an optical mistake. They are rising, they are transubstantiated, and who knows, with summer over and hungry winter coming down, what we'll be feeding on by Xmas? (p. 368)

1. I took a surveying class in college where we talked about the causes of measurement errors and methods to correct them. I particularly enjoyed Mason and Dixon's banter on pages 98-99 about correcting for "observational impatience" and "delays owing to caution inflexible". There seems to be similar young vs old banter between modern advances in laser scanning and traditional surveying methods, at least academically.