Hi BrokenSmile,
That "sudo" command may not be installed on your N900. In that case, make sure you have suduser tools installed before running it.
You could also try running "sudo gainroot" before entering "initctl emit AppLockStartDaemon"

In other news, the GUI is going to take a bit longer as I have decided to teach myself QML on this project. Will keep you all updated with the progress when there is something to show for it.