To Chloe: I think the outcome of this issue depends on the way MOULA/OSU pans out, in terms of our IP rights, and our/cyan's control over the inclusion of explorer ages on the official shard.
One proposed model is that projects go through a more-or-less "official" QA process with the guild(s), and Cyan presides. If we go with this, then we won't be faced with 60+ ages all ready for inclusion at once. They will go through some kind of revision and approval process (possibly format conversion as well).
I would love to see a system in place where ages are constructively checked by each guild for debug, canon (where applicable) and aesthetics. Then, the writer works with the guilds to establish the age's place in the cavern and in the community, whether it be hidden in a ruined building, in a restored office, in a museum, library or nexus, or behind the uh... wall of doom. They might create a new area, and IMO this kind of cavern expansion is a feasible and worthy pursuit, again, depending on the degree of modification/expansion we are allowed, and providing the guilds aren't swamped with too many projects at once. Writers could opt out, of course, but those who wish to be involved should be allowed to develop this kind of rich content without having to subscribe to a nexus.
What comes to mind are the writer/restorers who have their own base of operations, like Whilyam, Tweek/TTP, and you (Chloe Rhodes). Perhaps these places could be integrated with the cavern-- real, walkable buildings with ages inside, like the museum and the library.
As for explorers running around headless, isn't that what Myst/Uru is all about?

I think explorers could enjoy using clues to solve the puzzles and access the hard-to-access areas. And we should have the Guild of Cartographers for those who just want to get through it.
So... I hope that made sense and wasn't offensive. For the first age, I vote for Bimevi. Maybe we could make the stained-glass and put it in some neighborhoods.