Most windows, including the main window, feature keyboard shortcuts using the Alt key. You can now do almost everything using the keyboard except editing. If you press the Alt key the shortcut characters will appear underlined. The shortcuts will hide again when the Alt key is released. The shortcut key should be pressed before the Alt key is released.
In the main window, only the mixer section which has focus can be controlled using Alt shortcuts. A dot appears on the left hand side of the mixer section indicating it is focused. Tab and Shift+Tab can be used to move focus. Clicking a section (including any of its controls) will focus that section as well, so the track you're working on is typically focused automatically.
The Preferences and EQ windows have a similar focus mechanism.
Click to see Focus indicator (left) and Pan knob after pressing Alt+P (right)
Volume faders and rotary knobs can be edited using Alt shortcuts as well. An edit field appears in which a new value can be typed. Pressing Enter accepts the new value, Esc discards it.
Instead of typing a value you can use the up/down arrow keys to move the control. Note that you'll have to press Esc to accept this value, since Enter accepts the edit field's value.
Some examples:
Alt+F: open the track's file menu
Alt+Y: toggle the track's Play
Alt+C: toggle the track's Rec button
Alt+F1: open mixer section's first effect slot
