Actually there's some solid research behind this. If I recall correctly, people naturally find it much easier to remember which parts of a picture to hit rather than remembering a password.

Unfortunately, I can't find the research and sample that I remember reading about a while back--Google is spammed with Windows 8 stuff when I search for it and I'm terminally lazy. However, I definitely recall reading about research in this vein.

Absolutely. Mostly the extra clicks though with the slide up. If we already have to swipe a pattern to unlock, make that picture show up as soon as you wake the phone.

Yes.