It's still early in the month. The BZD and weather changes will happen closer to Halloween itself.

Usually 1 to 2 weeks before Halloween. There is no official date, it pretty much just happens when it happens, lol.

It's usually 30 or 31 days. The game doesn't actually count days since you registered; instead, it waits until the same day of the next month. So if you registered today, October 13th, (AND logged into the game client! Confirming your Email registration is not enough!) your deer should grow on November 13th at around the same time as you first logged into the game client.

Nothing wrong with questions! We have lots of answers :3

Mini deer is a deer who wears the mini-spell. They're half the size of a normal deer. A fawn can wear the mini-spell too, but it will wear off as fawns' spells do. A mini spell can be acquired by falling asleep in a mushroom circle and then it can be given to a deer. It comes along with shapeshifting spells [frog, raven, etc.], so you may not neccessarily give the mini spell for the first try.

Last year the BZD came first time on the 20th, but a few years back from what I've heard his first appearance was on the 15th. He's surronded by thick fog and really a lot of deer. Sometimes the whole forest may change a little. He's really most of the time asleep but perhaps you could catch him awake like I did last year. ;D