It’s been a while since I first went to a Category (such as How-To or Support) so I don’t recall exactly how it works but I believe Discourse (or forum software) shows topics in :
- Oldest-to-newest post order on first viewing
- Newest-to-oldest post order after after first viewing
I’m not aware of any “pinning” feature - the closest I can think of would be bookmarks, but they are user specific.
As far as log posting policies, I don’t know that there are any other than to try and scrub any personally identifiable data (passwords, email addresses, IP addresses, etc.) and what’s covered in the FAQ and here: