Wi-Fi on/off would be a GREAT app! That way when you are away from your "networks" you don't have to worry about the Wi-Fi radio searching and eating you battery when it doesn't need to. But currently it can't be done...
Device off.... you might could get if you trun your device off at night, or maybe at work if you aren't allowed to take it in the building. But the API isn't available for that.
Device on.... I can see you might want to turn you device on in the morning or when you get off your restrictive job. But when a BlackBerry is off, it is off.
I believe that there is one for WiFi based on GPS location, also does NFC and Bluetooth I think :s
As for auto power on/off, I don't think there is one. I know that BBOS 7 or 6 used to have a feature built in to the OS that did this. My sisters 9300 used to shut off everyday at 2:30 PM and she couldn't figure it out lol