I think you'd be surprised at how much depth a few committed (read: crazy) fans could come up with, were they unleashed. After all, a large part of the time Tolkien spent was in establishing all those "steriotypical" concepts, and he mostly just had the support of the other Inklings, whereas we have several hundred people on this forum, with atleast 100 regulars.
I don't have any steriotype against writers, not at all, but I wasn't daring to hope that anyone would be making Dominions: The Movie
More thematic music would also, ofcourse, be appreciated, as would poetry, especially if both had pseudohistorical significance.
I'm not sure we need languages, as most of the cultures here are based atleast in part on real world cultures, with languages of their own. I'd be happy to create a few languages, though-atleast alphabets and small vocabularies, as well as calendars. I have some amount of experience there.
Johan seems to like good stories-he expressed so towards DrPraetorius's hoburg story-so maybe we can entice him in that way.