I would assume that the main characters are the two friends. One is the protagonist, the person whose perspective we are seeing the story from, and the other is the friend who is no longer in their life as closely. There might also be some secondary characters who play a role in the events that led to the friendship changing, like other mutual friends or family members who influenced the situation.
The main theme could be about lost friendship. It might explore the reasons why a friend has drifted away, like changes in life circumstances, differences in values, or simply growing apart over time.
I'm not sure without reading the story, but it could be a protagonist who is haunted by the 'one that got away' and perhaps a secondary character who was part of the situation that led to the loss.
The main theme could be about lost opportunities. It might revolve around a character who misses out on something or someone important, like a relationship or a chance at a better life.
Since I don't have access to the 'an old friend short story', I can't say for certain. But usually in such a story, the main characters would be the old friends themselves. There could also be secondary characters like family members or mutual friends who play a role in their relationship, either supporting or causing some sort of friction between the two main friends.
Since we have no information about the 'a little friend short story' other than its title, we can only make assumptions. The main character is likely to be the 'little friend'. This could be a young child, perhaps a boy or a girl. There may be other characters like a wise old man or woman in the neighborhood who gives advice to the little friend. Or there could be a group of children who are friends with the main character and they all go on adventures together, sharing joys and sorrows.
In the 'false friend short story', the main character is often the victim of the false friend's actions. This character is usually trusting and naive at the start. The false friend is the key antagonist. They may seem friendly and charming on the surface but are hiding their true selves. Additionally, there may be a sidekick or confidant of the main character who might notice something strange about the false friend earlier on and try to warn the main character, adding an extra layer of drama to the story.
Since I don't know the specific story, it could be two friends, perhaps named John and Tom. John could be the one in need and Tom could be the helper.
I'm not entirely sure as I haven't read it recently, but typically in such a story, there would be family members like a mother, father, and maybe some children. They would be the main characters who experience the supposed ghost encounter.
I'm not sure as I haven't read the story. But it could be a traveler who is stuck in a foreign place during Christmas.
It's not a true story. It's likely a fictional creation made up to entertain or convey certain emotions and themes.