Yes, they could be. Many movies require a love story to add an emotional touch. They might be directors, screenwriters, or actors working on creating that romantic plot.
Yes, he has. Markiplier often does unique and entertaining segments, and this could be one of them. He likes to interact with different types of content related to his fan base, and reading fanfics, even the not - so - good ones, is a way to do that.
Well, staying true to the essence of the novel is a big challenge. Sometimes, directors may misinterpret the author's intentions. And then there's the casting. Finding actors who can embody the complex characters from the novel is not easy. Costumes and settings also need to be carefully designed to match the world created in the novel. If they get these wrong, it can take away from the overall feel of the movie based on the novel.
To make a movie fictional, you need things like invented characters with unique traits and abilities, and a plot that's not based on actual events. Sometimes, it's the combination of these elements that takes a movie into the fictional realm.