Very cool. A super useful feature of similar browsers like the page of the CIDOC-CRM [1] is to list all properties, **including inherited ones** (in the CIDOC-CRM page, click on a class, and click on "Show all properties" next to its title).
It took me a while to understand that your navigator is actually showing the same thing, by listing inherited attributes and relations.
When listing the relations, it seems a bit misleading to list the explicit range along with all inherited ones (e.g. when the range is Thing, then all entities are listed). Maybe you could distinguish between explicit range, and inherited ones ? similarly, when listing the relations, you could distinguish between the ones explicitly attached at this level, and the inherited ones (and from which ancestor they are inherited - this is very explicit in what is shown for the attributes, but not as explicit for the display of the relations).
Similarly, on a property page, giving all inherited classes as domain and ranges is misleading. The domain of R016 has successor is not Agent or Person or Group or Mechanism or Family, etc. The domain is just Agent. Of course subclasses could be listed as well, but just as a help to browse quicker, and they should be clearly marked differently.
Kind Regards
Thomas