Re. recent mockups of navbox and toolbox:
Those are nice. I want to encourage users to keep doing this - from a developers standpoint it is far more useful than a simple feature request. Additionally it forces you to consider how the feature should be added, instead of just blindly adding a feature without consideration.
A navigator/overview widget would be most useful in the compositor. Might be a fun little development project. As for the radial toolbox, I’m sure you know that Matt Ebb already did an implementation for 2.4x. Hopefully he’ll have time to revisit it after 2.5 starts to become more stable and polished.