Hello Nick - thanks for your valuable contribution. Yes I have seen the approach you have mentioned (spread sheets), and that is effective in smaller deployments, but may not be as such for larger deployments. As you have seen there isn't always one approach to implementing best practices. QDF is one of those approaches (consolidated from customer, partner and employee experiences) and as it continues to evolve, can become a standard and adopted in an enterprise. The Variable Editor supports the QlikView Deployment Framework only, and there aren't any plans to have it work independently at the moment. That does not mean it could not be adapted to what you want though. Your idea is a good one and should be posted in the ideas section of this group for considerations by QDF's developers and possibly other independent developers.
Please let us know if you have any other questions.
Senior Product Technical Manager
QlikView and QlikView Expressor
Follow me on Twitter @mtarallo