Hi!
I could definitely see a usecase for 1) and maybe for 2). For example, let's say i remember that one movie that Rutger Hauer played in, just searching for 'movie rutger hauer' gives back nothing:
https://www.wikidata.org/w/index.php?search=movie+rutger+hauer
While Wikipedia gives back quite a nice list of options:
https://en.wikipedia.org/w/index.php?search=movie+rutger+hauer
Well, this is not going to change with the work we're discussing. The reason you don't get anything from Wikidata is because "movie" and "rutger hauer" are labels from different documents and ElasticSearch does not do joins. We only index each document in itself, and possibly some additional data, but indexing labels from other documents is now beyond what we're doing. We could certainly discuss it but that would be separate (and much bigger) discussion.
If we would index item properties as well, you could get back Blade Runner (Q184843) which has Rutger Hauer as one of its 'cast member' values.
You could, but not by asking something like "movie rutger hauer", at least not without a lot of additional work. Indexing "cast member" would get you a step closer, but only a tiny step and there are a number of other steps to take before that can work.