Thanks, and sorry, that is a bit unclear. When selecting a tool, the mouse click seems to work more consistently than attempting to select the same tool by pressing the keyboard shortcut -- for example, v to get the pointer tool (I assume this is because the keyboard shortcut is necessarily more context dependent than the mouse click). If I could assign the mouse-click selection action to a function key, I could then assign that key to one of the five buttons on my mouse, which would speed some things up).
Make sense?