Variable. There is certainly potential for a high level of science in the construction, maintenance, and mere feasibility of these big structures—it's quite the engineering feat—and some stories will engage with the science and technology of the structures. But not all stories

Moderate. Really big structures in space have social significance. What does living on an artificial world mean for society? How does this setting effect politics and social structures?

Variable. With such an emphasis on setting, characterization can sometimes be less of priority for the story. Yet, in other stories the setting is just a background, which means there will be room for the author to spend some time on character development. It really just depends on the author's intentions and ability to balance the exploration of the really big structure with the rest of the story

Variable. Like characterization, plot may or may not be super important to the story. And while many stories will incorporate Bigger Than Worlds, it's more of a setting than a plot requirement and so plots vary. Often, plots are not too complex so that readers have plenty of time to explore the really big structure

Variable. The level of violence depends more on story than on setting and because this sub-genre is defined by setting, the level of violence is completely flexible