In some fanfictions, Bakugo can become more empathetic. For example, if he experiences a situation where he realizes the pain he's caused Deku over the years. His aggressive nature might soften as he starts to understand Deku better. Deku, on the other hand, could become more assertive. Instead of always being the timid one, he might stand up to Bakugo more firmly in fanfiction scenarios.
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.
One popular fanfiction concept could be Deku proving his worth without a quirk in the Bakudeku relationship. Maybe he uses his intelligence and strategic thinking to assist Bakugo in battles. For example, he could analyze opponents' weaknesses and come up with battle plans that Bakugo can execute. This would show that even without a quirk, Deku is an important part of their duo.
One common theme is friendship. Despite their initial rivalry, fanfics often explore how Bakugo and Deku form a deep bond. Another theme is growth. They both grow as heroes and as people in these stories. For example, Bakugo learning to control his temper and Deku getting stronger.