There is no way to know for certain without reading the 'love on the rocks novel'. However, generally in such novels, there are often two main characters who are in love or were in love. They could be of different backgrounds, personalities, and ages. Maybe one is more impulsive while the other is more reserved. And there might also be secondary characters like their best friends who either support or complicate their relationship further.
I'm not sure as I haven't read it, but they could be a couple facing relationship issues.
I don't know for sure as I haven't read the novel. But typically, there could be a protagonist who is directly involved with the 'cry' in some way. Maybe a young person who is brave enough to make that cry heard or a person who is on a quest to understand the significance of the cry.
The main theme could be about the challenges in a relationship. It might explore how love can face difficulties and how the characters deal with them.
Since I don't know the exact story, it's difficult to say. But it could be the hikers who are the main characters if it's a story about a hiking adventure and the danger of falling rocks.
Since I don't know the exact 'pocket full of rocks story', it could be a young adventurer as the main character. Maybe someone like Tom, who stumbles upon a pocket full of mysterious rocks.
Since it's an OC fanfic, the main characters are likely to be the original characters created by the author. They could be pirates with unique skills or personalities.
The 'big rocks short story' doesn't feature highly - developed, named characters in the way a story with a complex plot would. The main character is essentially an everyman or everywoman figure. This figure is the one who has to deal with the task of fitting big rocks (symbolizing important life aspects) into a container. It's about the average person who is being taught the lesson of prioritizing important things over the less important, so the main character is more of a representative of all of us in the context of learning about priorities.
The main characters in the 'big rocks balancing acts story' are unknown without further details. But we can imagine different scenarios. For example, it could be a team of engineers in a construction project where they have to balance huge rocks for a foundation. They would be the main characters as they are responsible for the crucial task of balancing the big rocks. Or it could be a story about a young adventurer who discovers an ancient place with big rocks that need to be balanced in a certain way to unlock a mystery. In this case, the adventurer would be the main character, trying to figure out the rules of the balancing act and facing the challenges that come with it.
In the 'Watch out for falling rocks story', the main character could be a geologist. He is studying the rock formations in an area prone to rockfalls. His work requires him to be constantly on the lookout for falling rocks while also trying to collect data and make important geological discoveries.
Since I don't know the story, it's impossible to say for sure who the main characters are. It could be a solitary person who is the focus, someone who has this strange preoccupation with street rocks while reading.
Since I don't know the exact 'pockets full of rocks story', it's hard to say who the characters are. It could be a young boy as the main character who fills his pockets with rocks out of curiosity. Maybe there's an older figure, like a grandfather, who tries to teach the boy why it's not a good idea to carry so many rocks around.