Interesting idea. Can you make it so that when I click in the card it automatically goes into edit mode? Having to click an "edit" button really slows things down.
Single click would be easier, but since we have drag-and-drop, and sometimes use clicking just for navigation, we have to use double-click to edit.
(unless you have a better approach in mind?)
PS: Also, once you get used to them, the keyboard shortcuts lets you navigate & edit pretty quickly.
Also, just now I was seeing other people's cards showing up in my tree. When I switched trees, it corrected itself.