Rarity would be all over the gossipy bit~ It's all harmless fun, really! So I'd definitely be interested in signing her up for ICly being a part of it!

I think a single post would be nice, with maybe multiple threads with the appropriate subjects for people to reply to? Also, once a week might be a little much for some people to handle and have the time to reply to before the next one, so either once or twice a month seems reasonable to me.