Thanks! I've moved some pages to the new namespace until a security throttle was reached.
About those keywords: rather than sending visitors directly to the elaborate and potentially confusing Special:Ask, it would be great if we had a dedicated page with a simple interface. A tried recipe, at least for me, is to have a page like that read the relevant keyword from the url and to show other keywords in a separate panel for further queries. The Urlgetparameter extension (not currently installed) is a simple tool that allows you to implement this. Special:Ask could be kept in there as a sort of advanced mode, of course.
Whether or not this can be used in conjunction with the Filtered format is something I'm curious to find out, but pending a number of future fixes it may not be a terribly good idea to give it such a prominent role (yet).
You must have been really fast moving stuff. Since no extra throttle was configured for moving you must have hit a default set by MediaWiki core. Keep on fighting.
About the keywords: I have now installed the UrlGetParameters extension to allow your approach work. However, the set query feature which works with templates should allow for a similar solution too. A searcher is indeed forwarded to special page Ask but the template view allows to also serve keywords which are again doing a set query. Thus the user does not really have to do anything than to hop from keyword to keyword and explore the different results.
Anyways, thanks for your effort and I am curious to see how it will work out.