One thing that would be nice about tikiwiki is that you can use it to send pages to another wiki, i.e. another instance of tikiwiki on a server. So you could possibly set it up to automatically post parts of your on-iLiad wiki to a server-based wiki somewhere, either as a backup or as a way of publishing work automatically. Just a thought. Something really simple like usemod or tiddlywiki would handle everything on the iLiad if you don't need to export.
Regarding WYSIWYG editing of html or wiki pages, tikiwiki has a WYSIWYG editor, but only for blogs. See
http://meta.wikimedia.org/wiki/WYSIWYG_editor for an overview.