Usability

If I don't have JavaScript, I should see the "raw" version of the target page: Observed by one of Eric's users: if you have JS turned off, you currently get a blank page. Can we do something about that?

When I remove a Property from a Model, I should be able to delete it: Frequently, the reason to remove a Property from a Model is that I decide I didn't want quite that Property at all. Intuitively, I want to delete that Property and free up the namespace.