Yes, it has a sensor in the stick grip to know when your hand is on it or not.I have had NO heat problems with mine, but Logitech suggests you turn the power adapter off when you are not using it or any of their FF controllers. And this is something I always do anyway if it's something that does not need to be powered up 24/7, just a good rule of thumb to follow. I just use a small power strip with rocker switch so it's easy to do before I get up.Any FF motor startup noise is bypassed by plugging in the USB cord before you apply AC/DC converter power to the stick.

Can the stick be turned to control the side rudder or must this be done with the pedals only?

Pedals only. It doesn't have a twist function like some other HOTAS systems.

Can you make turns without pedals? Just using ailerons? Rudder trim potentiometer?

I've had 2 G940s now that overheat regularly while flying for about an hour. The force feedback cuts out and will not return until I quit the game and let it cool down for a bit. I'm waiting to see if Logitech will suggest yet another replacement product, or if this is just an inherent "feature." Apparently there IS a temperature sensor that will kill FFB if it gets too warm, but it shouldn't be constantly activating when flying for only an hour. Lots of people plan flights that last 10 hours, this sort of failure is unacceptable.If I can't get my hands on a working G940, there's no way I'll recommend this system to anyone.