A good rule of thumb is to use a dynamic sitemap that always re-populates with all of your pages. This way, you can avoid human error, and make sure you always have a clear map of all of your links for the search engines.
Up to 999 links is generally no problem for sitemaps, although it can be unsightly.
It’s an intriguing idea to me, and one I plan on exploring. The newest version of WordPress is very search-engine friendly, and the interface is enjoyable to use. With some decent content, we could be off and running, because let’s face it: directories don’t normally have content.
Can content, especially dynamic content be good for a directory? It indicates a lifeblood that might be lacking of other directories. This could turn them into just a “collection of links”. Without the human element, no directory can ever truly prosper.
It seems that Google does a very poor job of handling files that have been excluded by robots.txt. It seems that Google loves to display URLS only, for any file that they’ve visited from another file, even if that file is excluded explicity via robots.txt.
That behavior seems strange. Why have a wildcard to remove dynamic pages and then show the pages in a very untidy looking manner? The other thing I’ve noticed is that they never drop pages naturally, only if you use the URL removal tool.