For Goku's relationship with the other Z - Fighters, it could be a mixed bag. Some, like Piccolo, might see the tail as a potential weakness that enemies could target. So he might be constantly on Goku to protect it. On the other hand, Yamcha might be jealous that Goku has this unique feature that makes him stand out even more. However, overall, Goku's tail could also be a unifying factor. It could remind them all of Goku's alien origin and make them more aware of the vastness of the universe and the different species within it, which could strengthen their bond as a group.
The bear lost his tail because he was tricked by a fox. The fox told the bear to put his tail in the hole in the ice to catch fish, but when the ice froze, the bear's tail got stuck and broke off.
The bear lost his tail because of his own naivety. A fox tricked him into staying in a frozen hole for too long, causing his tail to freeze and break off.
Well, in a lot of fanfictions, the story might rewrite the rules of the Dragon Ball universe. So Goku could keep his tail simply because the author wants to explore different storylines with a tailed Goku. Maybe the author thinks it adds more to his character's appearance and abilities, like being able to use it as an extra limb in combat or for balance during his super - fast flying.
His tail might enhance his combat abilities in a few ways. Since Goku is part Saiyan and Saiyans are known for their agility, the tail could be an extension of that. He could potentially use it to sense movements around him, much like how some animals use their tails for that purpose. In combat, this could give him an edge in predicting attacks and reacting faster. Also, he could use it for quick strikes, like a whip, adding an unexpected element to his fighting style.
The bear lost his tail because he was tricked by a fox. The fox told him to put his tail in a hole to catch fish, but when the bear's tail was frozen in the ice, the fox pulled it off.
Well, Goku is a Saiyan, and Saiyans have a strong sense of family deep down, even if they don't always show it. When he meets his parents in this fanfiction, he could initially be in disbelief. But once he realizes it's real, he would embrace them wholeheartedly. He may even start to show off his strength and skills a bit, like a child showing off to his parents. And he would be excited to hear stories about their Saiyan race and how they ended up in the situations they did.
Another possibility is that a new form of training or power - up in the fanfiction is related to the tail. So Goku is made to keep it for his growth and development as a fighter.
If Goku never lost his tail, his powers and abilities might have developed differently. Maybe he would have retained some primal monkey-like traits that could have given him unique advantages or disadvantages in battles.