Regarding the postponed trick-or-treating, I've been thinking about this.
As much as I love Halloween, I would not be supportive of delayed trick-or-treating. All October, I put a lot of effort and love into my decorations. But on November 1st, I'm putting everything away and thinking about Thanksgiving. Without the elaborate decorations, I get less than 5 trick-or-treaters, which isn't really worth the bother. (Obviously, superstorms trump trick-or-treating, but how often does that happen? Unless you are in New England and get hit two years in a row.

)
Early trick or treating would be somewhat less annoying; at least I'd have a Saturday to set up, but it would make the actual holiday anticlimatic.
The difference between moving Halloween and moving Columbus Day is that Columbus Day is (a) a day off for many workers, (b) was moved to make a three-day weekend for those workers, thus profiting the tourist and retail industries, and (c) is permanently set as the second Monday in October. The date may change, but the position in the calendar doesn't. The equivilent would be to make Halloween the last Monday in October, or maybe the last Friday, since the problem seems to be going to school the next day. And you would have to make it national, or at least statewide, because the arbitrary declarations by individual communities is part of the irritation.