Hello! I work on the team that produced this - the BBC's Linked Data Platform. The data our team has can be split into two parts.
One is the metadata we store about Creative Works, which represent content created by the BBC (programmes, news articles, blog posts, video clips). This is probably the data that is of most interest to the public, but we haven't opened this up - not yet, anyway.
The second is Tag Concepts - things that Creative Works can be tagged with. That's what were surfacing on /things, and at the moment we're only not showing every bit of data we have for each thing.
The "Beta" label signifies that it's just a first version to gauge reaction and see what the public want from a site like this. We'll be looking at things like this thread to help us work out where we should go next.
Hey - I work on this. The main areas of the BBC that are using our Linked Data Platform at the moment are News, Sport and Music, which would explain the results you get for "Queen". As more teams in the organisation start using our system, you should see a wider variety of data accessible through the site.
We know the search isn't the greatest, and that's something we'd like to improve.