This was about ZIDs < 10k; people now can edit them but the Z2K2 is read-only (with no feedback that they can't edit it, oops, and they can't set e.g. labels for keys, double-oops), so this is Resolved.
Great, thanks. I was thinking about that second case while working on the new language selector, just created a task and pushed a small patch to allow editing all multilingual strings while in edit mode. This will need to be scoped down more as we add in more user permissions but it'll help in the short term.