Yes. In certain comic storylines, Black Panther and Captain America find themselves on opposing sides and engage in battles. The reasons for their fights vary and are often tied to complex story developments and character dynamics.
There are many great writers out there. Some popular ones are often those who are very active in fanfiction communities. For example, 'TheAvengerWriter' might be known for writing some great stories about them. They really capture the essence of both characters.
There might be a fanfiction where Captain America travels to Wakanda for some training and there he meets Black Panther. They learn from each other's fighting styles and form a deep friendship. As they train together, they discover a plot against Wakanda that they must prevent.
In the main comic continuity, Captain America has typically been depicted as a white character. However, there have been alternate storylines and versions where the role has been taken on by characters of different races.
Sure. In the comic universe, Isaiah Bradley has taken on the role of a black Captain America. This addition brought more diversity and new storylines to the Captain America mythos.
In the fanfiction, their relationship could be complex. They've been through so much together as comrades in the Avengers. As parents, they might have different parenting styles. Captain America could be more open and idealistic, while Black Widow is more cautious and practical. But they both love their child deeply and work together to keep the child safe from the threats that come from their superhero lives. For example, when the child wants to join a mission too early, they have to work out how to handle it as a couple.