Q1Touching the screen somewhere near the top right corner will turn it off or on.
This doesn't work on mine. This may be one of those things that only works if you start from the right place, ie you need a particular screen showing first, and it might also be dependent on whether you have (or have not) enabled the alternative skin. That's worth doing, BTW, it not only changes the look it also gives you some subtly different functionality like the ability to display a big analogue clock.
This topic was previously explored in this thread ...
http://clubjazz.org/forum/index.php?topic=7958.0... which also concluded that the brightness button was the thing to use, plus you also have to turn the volume down (or power-off the audio) if you want quiet.
Q2You might have found this by now, but if you touch the top menu icon (which
is top-right of the screen), you get the nag screen back so you can then OK it and it'll display something that may or may not be what was on it when you last turned it off.
Q3I completely agree with John Ratsey's comment.