If I erroneously launch some application that I didn't mean to launch, it's possible to close it by killing it from the console or the system monitor, but they cannot be closed from the icons-only task manager before being fully loaded. Would be nice if it would allow aborting application launch (closing an application while it is loading, without having to wait for it to load fully) from the right click menu of the application's icon like in Windows OS.
With possible options in settings window for confirmation and close On middle click