Great Post Richard, thanks for adding your voice to the conversation...
I have been to a number of conferences over the years where those in the Cement Industry try (erroneously I would suggest) to compare modern portland cements (OPC) to the vintage cements and pozzolanics of acient Europe, Middle East,Asia, and even the wonderful Natural Rosendale Cements of New York state (now once again in production.) There is simply no comparison of modern OPC with natural and/or vintage cements/pozzolans/geopolymers as we still can not build anything like the Pantheon even today...This acient technology evades most (not all) contemporary builders.
I love your point about being under a tree on a robust layer of chips...It's wonderful I do agree and perhaps one of the best places to joint a frame!
As to wooden floors with nails...I could not agree more with your observation, and why I float and/or joint my wood floors to exclude any metal fasteners whenever possible. This turn in the conversation also reminds me of traditional Puncheon Floors
(of which I have restore and/or laid a few) and how they rest, just as you eluded too, on a clay or gravel dias often the same as the sill or plinth stones rest upon. This even has merit for our OP (EPops) as he could just frame the structure onto plinth or sills and lay an independent Puncheon Floor to work on. These are both very solid, yet forgiving to dropped tools and old backs (ha, ha.)
Clay (cobb, adobe, etc) floors to are still a common example throughout the built world even today. Probably one of the most common floor systems still employed by most vernacular builders (worldview) in domestic architecture at least for a section of the architecture and/or the entire ground floor areas.
EPops has lots of choices to choose from...