It would be a nice workflow enhancement to implement "sticky keys" ?
So a tool would be active only as long as the hotkey is pressed, and would switch back to the previous tool as soon as the hotkey is released ? It would cut the need for using hotkeys in half, and thus speeding up workflow. Only when a hotkey is pressed and released immediately, a tool is permanently activated.
For instance; while using the Node tool one could press and hold "Z" to activate the Zoom tool, zoom in, and simply release the "Z" key to get back to the Node tool. Much faster then having to press the "A" key again to get back to the Node tool.