The train crew must have already known that the girl would take a cup back to the stowaway child - the hot chocolate crew is so good and precise at their job that there is enough for every child - even when the girl hides a cup under her seat, she still gets a cup without the dancers losing their pace or wondering where the extra cup went.
The two hero children and the stowaway navigating through Santa's Workshop is accompanied by Christmas music from the '40s and '50s. What do the snippets that play from "Winter Wonderland", "Silver Bells", "It's Beginning to Look a Lot Like Christmas" and "Here Comes Santa Claus" all have in common? Listening to sleigh bells!
The time always being 11:55 PM during the kids' trek through Santa's Workshop makes sense when you realize they're at the North Pole, meaning they're constantly crossing timezones.
Speaking of the North Pole, the elf city's gigantic Christmas tree is parked exactly on that spot. This is shown by the giant compass rose inset in the pavement, which points South in all four directions around the tree's base.
In perhaps a rather brilliant move on the writers part, the Hobo making himself known to the Hero Boy becomes this. He was first scene riding under the cars when the Hero Girl's ticket went flying out the window, but he only showed himself to the lead protagonist when he was trying to cross the top of the train. Now where was the train heading? Flat Top Tunnel, a location where, according to a deleted scene, the Hobo was killed at. He wasn't just showing up to play Devil's Advocate for the Hero Boy and his doubts about Santa; he was trying to save him from the same fate he suffered! After all, there was but only one inch of clearance between the train and the tunnel's ceiling. Had he not warned him, the boy may have never even saw the tunnel was coming until it was too late.
Most rail fans would obviously wince at the Know-It-All Kid's inaccurate description of the locomotive, as Pere Marquette 1225 is not all of what he describes (notably her construction date, builder, and class). Of course, this is potentially a deliberate flub on the writers part, as the character's primary flaw is that he acts like he knows everything, but really knows very little. After all, the Conductor did punch the word "learn" on his ticket for a good reason.
Notice that when Santa Claus takes off, he makes multiple passes over the square before actually leaving. He's not showing off to the kids and elves, his sack is so large that he needs to build up enough airspeed and velocity to properly remain airborne.
One may wonder how Billy has failed to believe in Santa Claus all his life, not once ever received a present from him. But a child growing up and living in an impoverished home is unlikely to have faith in anything.
No matter what that present was, it's probably not going to change the fact that Billy has an unhappy home life and most likely a bleak future.
Watch the scene where the train goes down the very steep grade and slides on the ice. Then imagine what the ride was like for the other children. It was probably hell.
If a grown man and two children standing exposed at the front of the locomotive can manage to stay on with only one close call, I think everyone in the coaches will be safe. They probably loved the experience.
