Michael and everyone, I was once — for a few years, actually — part of a shared-land-use situation with three other households. Much of what you’ve described makes sense. Our “fly in the ointment” issue was that we were all young, between 25 and 30, and the household units (couples with kids) had not sorted themselves out realistically… things disintegrated.
But if you can provide & create the needed social stability, this co-op idea can flourish, I believe.
Among things that were definitely good in our experience were social companionship, multiple experience & viewpoints toward assessing situations, teaching & learning from one another and through shared endeavors, the energy-mulltiplying effect of ‘more hands on deck’ with certain ongoing projects, shared infrastructure like water system & larger gardening tools.
On the land, we had a shop with work benches, table saw, bandsaw, jointer, drill press, hand-wielded and portable powered hand tools, oxyacetylene torch rig, etc. Equipping a weatherized workshop in at least a basic way was essential to creating and maintaining the homestead. But if it had been an individual-household shop, paid for by one household, the shop in total would have been probably the most expensive single investment or piece of equipment’. (I know through experience, because after our shared-land situation broke up, I had to reinvest in a shop on my own over a period of years.)
At this point, I’ll offer a link to a discussion I’ve been trying to nurture here within the Homestead forum in Permies.com…
https://permies.com/t/62659/homestead-workshop-shed-situation
Please contribute to that thread, if you can. :)