I would say shared activities, meeting and community is the total centre point. You want your community to have regular contact with each other.
Lots of walking and sunshine would be another.
Theres no reason to eschew technology in my beleif (humans have always been tool users, makers and thinkers), but technology, in terms of form, function and use, should be adapted for the human, rather than the human adapted for the technology.
Agriculture has benefits such as a connection to nature and the seasons (and bringing people together). Its not something to regect outright. In fact I would deepen its benefits by trying to establish said community very close to native forest/bush, where the community can learn about local plants and animals, connect to nature etc.
I would also suggest that a paleo community should be connected under some kind of philosophy connecting them to the natural world. A sense of mystery, awe and also a spiritual connection to life and living things is part of our old way of life. Now in the modern day, we kind of preclude superstition and metaphysics, but philosophy is not precluded. What that might mean, ill leave up to you.
Of course outright huntergathering and survival skills arent nessasary anymore. But thats no reason not to have someone there to teach these skills a little, just to deepen the connection with nature. In this respect, it may also help to have a herbalist, who is familiar with local plants.
In terms of psychology, the are three pillars of subjective wellbeing - freedom from undue restrictions, a sense of place and purpose, and community. Recreating that closer community and a role in it, and also a connection to the world around them will be key IMO to forfilling our emotional needs.