Thanks @jimb! Very glad to hear.
Mattermost is designed as a continuous archive, not supported right now. Can you share more about how important this is? Messages from a year ago shouldn't affect load times.
Not yet, there's /online and /offline slash commands proposed in a design under review, these are feature changes where code contributions are welcome.
Correct, you can add a feature idea to be upvoted on this if there isn't one already.
No permissions on channels right now, you can add a feature idea to be upvoted on this if there isn't one already.
That said, Town Square is typically used for announcements and you can rename the channel to "Announcements Only".
If someone on your team is over posting in the Announcements channel, it's probably more a people problem than a software problem.
You can add a feature idea to be upvoted on this if there isn't one already.