In Homelander x Starlight fanfiction, one common theme could be the struggle for Starlight to maintain her integrity in a world dominated by Homelander's influence. Writers might create scenarios where she tries to change him or at least limit his more tyrannical tendencies. Another aspect could be the star - crossed lovers idea, where their relationship is doomed due to their opposing positions in the superhero world.
One popular trope is the 'enemies to lovers' trope. Given their different outlooks and Homelander's often villainous actions, this is a common way to build a relationship in fanfiction. Another is the 'power imbalance' trope, where Starlight has to deal with Homelander's overwhelming power.
Definitely. The comic version of Homelander is portrayed as having greater strength and capabilities. This is evident in his confrontations and the scale of his power displays throughout the comic series.