Space marines in trademark science fiction are usually depicted as the elite of the military forces in a science - fictional universe. Their physical strength is often augmented through genetic engineering or advanced training regimens. They have a distinct look, with their armor being a recognizable symbol. They are not just fighters but also symbols of the human (or whatever species they represent) presence in space. Their stories often involve themes of heroism, sacrifice, and the exploration and protection of the unknown regions of space. They interact with a wide range of characters, from scientists who develop their equipment to the civilians they are sworn to protect.
Space marines are usually more highly specialized. While regular soldiers might be trained for general combat on Earth, space marines are trained for the unique challenges of space, like zero - gravity combat and dealing with alien life forms.
There are indeed. A lot of fanfictions might explore the relationships of female Skaven. They could be in conflict with male Skaven over power within the clan, or form unexpected alliances with other races in the Warhammer universe for mutual benefit. It's really fascinating to see how different authors envision their characters.