So, I've another question: Is it possible to have a keyboard shortcut to close the current active window the same way it'd be closed when clicking the 'x' in the task switcher? What happens after this I don't really care about, being left in the task switcher would be ok.

Would launching task switcher and then sending the signal to close newest window do the trick?

I'll have a go at this later tonight myself if no one can answer and report my progress.