I like that you think big. Honestly even with just elasticsearch I bet a savvy user could put together advanced queries (outside of kibana) that do a lot of cool things.
Maybe as a starting point I can come up with a simple way to expose the ES Search API directly (perhaps for a small fee) so that anyone can build more advanced queries than our search API/kibana/NIP-50.
Might need to beef up that machine though :)