Hi all,
I agree that creating such a UI should not be left to WMF or WMDE developers. The SPARQL web api is there for everybody to use. One could also start from general SPARQL tools such as YASGUI (about.yasgui.org) as a basis for SPARQL editor.
An extra step should not be needed. Users would just use a query page like the one we have now. Only the display of the result table would be modified so that there is a language selector above the table: if a language is selected, all URIs that refer to Wikidata entities will get a suitable label as their anchor text. One could also have a the option to select "no language" where only the item ids are shown.
as I announced last week I've been doing some experiments which are pretty in line with these ideas. You can try this example:
wikisparql.org/sparql?query=DESCRIBE+<http%3A%2F%2Fwww.wikidata.org%2Fentity%2FQ1>
Also, on the endpoint page I've added a little widget which uses a labelling service (not a SPARQL one) to help finding entities from text search. I think it might help to get started with SPARQL along with example queries.
Let me know if it might be of interest, these are just experiments and can be improved in many ways (and I'm not a front-end developer :-)).
Nicola