Hi!
None of these features are present on the minimum required versions of Mediawiki, or the latest version available on WMF servers-- but I wonder if people- Mediawiki hackers and Tools creators- would be interested on doing those?
It would be interesting to see how this can work in deepcategory searches - we now have a keyword for it (driven by SPARQL for now) and what would happen if it is ported to SQL. If we get it on labs db replicas, we could set up mediawiki so that we could test how good is it on real data. Thanks for posting about it!