This is a complex subject and i appreciate JohnMu raising it in such detail.
I've wondered why Google restricts the geo targeting of specific URL's to one additional country and doesnt consider opening this up.
Maybe some day Google will consider displaying a ccTLD in the global results with more systematic relability in conjunction with webmasters than it currently does. It seems a bit hit and miss at the moment.
Should Google open this up via WMT and allow webmasters much more flexibility in providing signals to Google via this panel , and/or provide tag recognition to signal the territories to be targeted? Managing dupicate content would seem to be a lot easier with this.