Hello,
We at the consulting company WikiWorks are neither Wikibase users nor developers (other than having created some tools around SPARQL queries), but we do think quite a lot about user interface relating to structured data, especially within MediaWiki. Recently, we have been thinking about how to improve the Wikibase interface, to get around its limitations - such as the lack of on-wiki queries. We realized that there are already tools that can help with some of these challenges, and other tools that it would be a good idea to create. We put all our thoughts together into one proposed suite, which we named "Enhanced Wikibase". You can read about it here:
https://wikiworks.com/enhanced-wikibase.html
Hopefully these ideas will be helpful to anyone trying to make their Wikibase installation easier to use. Any questions or comments are also welcome.
-Yaron