Another theme is growth. Both characters grow as heroes and as individuals. In these fanfics, you can see how they influence each other's development, whether it's in terms of their quirk usage or their mental strength. For example, Deku might inspire Bakugo to be more selfless in battle, and Bakugo might push Deku to be more assertive.
One great 'bakugo x deku fanfic' is 'A New Bond'. It focuses on their relationship evolving from rivals to friends and then something more. The story beautifully captures their character growth and how they support each other in difficult times.
No way. The manga portrays their connection through mutual respect and competition in their journey to become great heroes. A kiss is not part of that narrative at all.