I have no idea if it's possible to alter with the site's current infrastructure, but I would love to see an improvement to the search function. It's great we can filter by specific forums and post types. What's not so great is not being able to sort results. You can search for something like 'urban fantasy,' and your first ten results will be from wildly different histories: anywhere from a couple months to 4, 5, 6 years or more. 

What would be great is the ability to sort results by date, so we can search for specific kinds of RPs or topics being discussed closer to the present, rather than slogging through pages of years gone by. It would also be nice to be able to search thread titles separately from post bodies.