Thanks for the nice summary!
I was also looking into a good place for (user-wide) activation info storage (we want an application to be activated for all users on the system, not just the one who ran the installer and activated it).
What we’ve been doing for “shared, read/write”, is use the /Library/Application Support/[Manufacturer]/[Product]
folder for that as well, but have the installer (also the superb Pachages tool here) create our [Product]
folder with fully open permissions (drwxrwxrwx), so that the app can then also write in there, not only read. There no readable info in the files stored there, but I’ve never really liked that, so moving these files to a folder in /Users/Shared
indeed seems to be the way to go.
Thanks for sharing this info!