Well, clearly Jim and Tim are main characters. They are the ones the fanfiction likely focuses on in relation to the Kim Possible universe. They are known for their inventive and sometimes zany ideas.
One idea could be that Jim and Tim create a new invention that accidentally causes chaos in Kim's crime - fighting world. For example, it might disrupt her communication devices during an important mission.
One possible ending is that Tim Drake realizes he made a mistake by walking away and returns to his old life. He might come back with a new perspective and be even more effective as a hero. Another ending could be that he finds a new purpose outside of the superhero world and is content with his new life. He could be living a normal life, but still using his skills in a different way, like helping the local community in non - superhero ways.
One possible theme could be growth. As the story progresses in part 3, Jim might be growing as a person, learning more about responsibility on the farm.
The theme of discovery is likely. They could be discovering new small animals and learning about them. Also, kindness towards the small animals would be another possible theme.
A plotline could involve a love triangle. For example, Kelly is interested in Jim, but Jim is already in a relationship with someone else, and Kelly has to compete for his affections. Or perhaps Jim is initially oblivious to Kelly's feelings, and she has to find creative ways to make him notice her.
Maybe Jim is the protagonist who goes through various adventures and experiences. Or, he could be a key figure influencing the events in the story. Without more details, it's hard to say exactly.
One possibility is that Tim Kempton had a bet with his friends about how many Whoppers he could eat in a certain time. So the story could be about his attempt to win the bet, whether he succeeded or not and the hilarious moments during the process.
Since Tim Duncan was not a well - known trash talker, any story would be quite rare. However, perhaps in a game where his team was being underestimated. He could have said to an opposing player, 'You don't know who you're dealing with.' It might have been a response to an opponent's overconfident behavior. Or during a game where he was having an amazing performance and an opposing player was trying to get in his head, he might have replied with 'Your mind games won't work on me. I'll keep scoring.' These are just made - up examples as there's no one - famous - specific trash talk story associated with him.
They would become more protective of each other. Jim would be extra vigilant in keeping Claire safe from any threats, troll or human. Claire, on the other hand, would be more concerned about Jim not overexerting himself in his Trollhunter duties.