My phone is always on, but on silent. I never use my phone at all, but I keep it on all the time just so it's convient when I need to use it when there's an emergancy or something important.
I turn it off if I'm at a movie, or if I'm out and its battery is low. Other than that, it's pretty much always on. My mother would worry if she tried to contact me and didn't hear back, and I don't like worrying her unnecessarily.
Like, I barely ever use it but it's always switched on. Not everybody leaves messages if your phone is turned off, so at the very least it's better to leave it on and put it on silent so I know if somebody has rang.
Very rarely. Only usually when it dies or when my internet is slow and acting weird, usually turning it off and back on helps get it back to normal again.
She also has a habit of leaving music playing when she does this.
My phone should really just be superglued to my hand. I never turn it off, although I frequently need to restart it. When I'm in bed it sits next to me on a low volume with certain notifications turned off or muted to restrict who can contact me. Although I have a bad habit of turning text notifications off when I go to sleep and then forgetting to turn them back on for several days. Luckily most people realise that Skype and Kik are the best ways to get hold of me anyway.