I was brought up in Aberdeen, and we dressed up and went "guising" down our street - to our neighbours houses where we played games and performed our party piece. We weren't particularly ghoulish and made our own costumes (I remember being a TV set one year).
We'd often get rewarded with something edible, but it was more of a spread-out party.
I think the issue with trick-or-treat (as it is practised in the UK) is that it's seen as a licence to threaten people rather than the old model of making an effort to put on a show to entertain and have a party.
"Carol" singers (for us) are the same - usually a pair of boys singing half a verse of "We Wish You a Merry Christmas" and hoping for money (Maybe next time we'll have to be ready at the door with the Oxford Book Of Carols and sing something medieval back and see if they give us some money...
) However, there is a long-established tradition especially in the country of larger groups going round singing to raise money for charity. I've been in a group singing carols for the Medical Foundation in Birmingham New Street station concourse... not perhaps the easiest place!
