I've updated to prioritize making an intro course first and to do active maintenance on a database of people I coordinate using my private CRM instead of having people sign up and have forum profiles for now.
Things are largely shifted to the Coordination Studies Signal Group, if anyone wants to join, email me.
I think my strategy will be to spend a bunch of time using the site with people I know to work out the features more.
Then later do a proper launch with precommits of 30-50 users and crossposting etc.
I think there's some heuristic of "Don't make it look small / empty", but there's also "Get user feedback as much as possible" and "Don't let perfect be the enemy of the good"
Related: Makes me wonder if a heuristics exchange might be cool and what some optional structure on sharing should be for that. Probably something like situation description, heuristic description, some kind optional evidence/ examples of why and where the heuristic works.