Yes, e-mails and phone calls seem to be during office hours. I got an e-mail and a phone call within 10 minutes of each other the day after my stage 3 (and just after 5pm for more details).
Not necessarily.
I got my confirmation phone call to say I'd passed Stage 3 at 6:30pm
From what I've heard they only phone you if you've passed. Otherwise you only get an email. For the few days I was waiting, I was panicking every time someone sent me a text (As I get a text when NATS email me) and getting frantically excited every time my phone rang!