The UI-Widgets Package library has a couple of nodes.

Widget shortcut – can assign shortcuts to the widget as a whole
Widget toolbar – opens a toolbar when the widget is active and closes it along with the widget

The shortcuts only seems to work with simple lower case characters, numbers and some lower case symbols.
The toolbar only works with 1 toolbar at a time. More than one and they sit on top of each other. It seems to open the toolbar near the mouse position.