Not quite right, your home phone may need plugged in, but that's for remembering numbers, hands free etc. The actual phone part gets its power from the line and doesn't have its own, and the exchange has a mains, battery & generator backup supply which is why the phone usually works during power outages. As an aside power outages are initially pinpointed by the sudden burst of calls, which are tagged geographically & alert the power company to where there's a problem. (Edit - rearead your post and now think you meant the phone system had it's own supply not the phone - which is right - so sorry for misraeding).
I totally agree on the gizmos.
Re 112 video there's nothing special in place in the UK that's not already there for 999, the addition of 112 was an OFCOM directive a few years back. He's got some of what happens kind of right (like trunk reservation for emergency calls in congestion situations), and some wrong (there isn't more bandwidth for text than voice).