A very minor comment to help new users who press f12 by mistake:
how about just saying "Hit RETURN to re-enter the desktop" before
giving the *-prompt on F12? It's an extra line taken up but I
don't think the pros will mind too much, and I think it might
help new folk just a little?

What are the chances of optimising the redraw of a scroll bar
so it's only the changing ends that get redrawn? When dragging
over some windows, the scroll bar flickers more than anything else.
