Ubuntu – How to change the shortcut key to launch the dash

See better answer below this one.

You must bind the action to the Super's scancode or keycode; normal hotkeys record the state of the modifier keys and throw away their keypress events; so you never see something that reacts to just pressing Alt, but instead to the A key plus the Alt key's recorded state.

The hotkey library in use is libgtkhotkey (0.2 on 12.04) and it doesn't support using the key press event from modifier's. You'd have to write your own patch to catch that and perhaps support such a thing in the signature format.

All tests with the existing signature format failed to produce anything but an error.

Parcial answer: to change some of the shortcuts you mention (Super + a, c, v,...) you need to edit the proper file ending with .scope that you'll find in /usr/share/unity/scopes (you need to be superuser in order to edit these files).

For example, if you want to reassign the shortcut super + a with the compiz manager you first need to find the file: /usr/share/unity/scopes/applications.scope and change the line: "Shortcut=a" by a letter you won't use ("Shortcut=n" for instance).

Hope it helps.