This initial journey would be great to solve, because otherwise it adds annoying friction in the initial phase. E.g. if you really need to force that admin can't have listings, then you could automatically create user account for the admin. I'm saying this because a lot of people that will want to create a market are doing that because they actually want to sell something and practically speaking that's the only way to really bootstrap the economy around the market.

Useful metric here would be the time from installation to the first listing...

Perfect, thanks! :)

For DNM there are more optimizations that you could consider to make it work well over Tor, like including initial css in the index.html response directly, so it doesn't have to make another request.