May I suggest some features that I find useful at other online forums?
1. New Post feature, that displays all new posts since your last log-in.
2. Subscribed Thread feature that emails you when someone posts a new message to a thread you have subscribed to.
3. User Profile feature that displays along with your user name and picture. Can be your country or a favorite saying...just to give more info on the people that visit the HL.
The first two would help with the problem that new posts to older threads are quickly buried by new topics, before the previous conversations are really finished! As the HL grows, the ability to sustain a thread on a topic will greatly help in searching the archives, otherwise you will get numerous hits as people keep reposting the same topics.