From your lists, I would suggest you include:
- Missing monster stats
- Lists of the few of the monsters suggested in the LBBs but not in any encounter table (androids, cyclopes, Martians, etc.) with brief bullet point outline of how to stat creatures out on one's own
- A Chainmail-derived combat/initiative procedure
- Slightly more detailed guidelines for making dungeons & wilderness
- Fleshed-out hireling rules, drawing on the wages listed in U&WA
- Naval combat
- Aerial Combat
- Castle building, mass combat
I would agree with you with regards to nothing in from the various Supplements. Let this be a kind of template for folks to use to build their own "supplements."
Fight on!