Glad you like it and thanks for your input regarding the landing page. There's definitely more work to do. What we're currently working on is some videos that will describe different use cases and how to use Nuclino. The other points you mentioned will follow soon.

Currently, we don't have any importing functionality, but we'll work on that in the near future. It might also be possible that we will provide an API that allows users to create custom import scripts for arbitrary file formats.