DialAKneeThing is a lightning-fast, exploration-based hierarchy viewer, meant to scale from personal bookmarks all the way up to a replacement for large corporate web sites' nav pages / site maps.
As mentioned in the readme, it would be good to have the option of making sure you aren't sending users in circles.
Ironically our current test data, which was good for quick manual testing during prototype development, would fail this. So I guess this is tied to #10 as well.
This would still have to read the stored JS file, but the idea would be that the generated HTML itself wouldn't have any need for JS. Every page would redirect if JS was enabled to the SPA URL, but if not, would display via pure HTML+CSS.
Like a traditional navigation system, showing the path you've taken would be helpful to see (also for jumping back quickly, but it should be done with pushState integration if possible, I think.)