Well, often in such fanfictions, their love develops as they discover new things about each other. Maybe Ezra starts to notice Sabine's artistic side more and Sabine realizes Ezra's growth as a leader. Their mutual respect and admiration then turn into love. They might have a moment of realization during a quiet conversation under the stars, realizing they mean more to each other than just friends.
In the official Star Wars lore, Ezra doesn't kill Kanan. However, in some fanfiction, the story might take a very different and often dark turn. Fanfiction allows for a lot of creative liberties. But it's important to note that this goes against the general spirit of their relationship in the main Star Wars narrative.
There's no official statement in the Star Wars Rebels canon that Ezra hates fanfiction. Since fanfiction is a creation by the fans outside the official story, it's not something that's directly addressed in the show regarding Ezra's feelings. So, we can't really say he hates it based on the given source material.
Ezra could use his connection to the Force to manipulate the environment around him. For example, he could cause distractions by making objects move and then slip away while the Inquisitor is distracted.