For the challenges forum
How about you make it into a single forum, instead of one for the challenge and one for the response. The first post is the challenge and the responses come in the replies to the challenge.
I would say that the "challenges" needs to go at the top of the fanfiction section, not its current location at the bottom, let it be one of the first things people read about.
The only other thing I can think about is we need to change its name... "challenges" gets very little response to TFF while we have had many unofficial writing contests of short fics that have been very popular and highly active.