Both questions have been brought up in the past.
As for the first, we're open to suggestions. If you or anyone else can find and/or make a
template from SMF that is satisfactory, let us know. I've looked through them an nothing really jumped out, and Ive no talent for creating. Just no white/light text on a black/dark background - Madness can't handle that. Otherwise, suggest away.
As for new threads, you may be right. We have set a soft limit at 15 pages of comments, but it may be that locking older topics might encourage new posts... However I would guess that those that want to post have and/or do, and forcing people to make new topics isn't likely to encourage more posting, but thats just one man's opinion. If we get some real user input/participation, change is always possible.
We even have a whole board for these kinds of things, as well as a stickied thread called
Suggestion Box 
.