Re: Orphan pages
As far as I know, there's no way to delete orphan page en masse. This probably isn't normally necessary since orphan pages aren't inherently bad — they might not be linked to from a wiki page, and therefore are "orphans", but can still be linked to via a menu, category, tag, etc. You can go to tiki-orphan_pages.php ("Orphan pages" under "wiki" in the default menu) to list them, then delete any there that you want to.
-- Gary