I think it might be a good idea. Might also be wanky too, but that never stopped me from using the site. I cannot stand spnstoryfinders for the exact reason that you stated, but it wasn't hard for me to join a few days ago to track down a particular lost fic. It was torture to comply with the rule to go back at least 3 months (I think that was it) and find possible similar requests, but in the end after skip eight billion, I gave up after only really getting about 3 weeks back. However, I got a really prompt and accurate response so in the end, it works. And I don't have them on my flist, so I don't have to deal with the idiocy.

I would say that it would be great to have the community if the rules are very specific (re: no general requests) and it's well moded.