A great place to start is Archive of Our Own (AO3). It has a large collection of fanfiction, and you can easily search for 'healer deku fanfiction' there. There are filters you can use to sort by popularity, rating, etc.
One great 'healer deku fanfiction' is 'Deku's Healing Journey'. In this story, Deku discovers his hidden healing abilities and uses them to help his friends on the battlefield. It shows a different side of Deku, not just as a fighter but also as a healer, which is really cool.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.
I'm not entirely sure specifically what a 'urakaka x deku fanfic' is about without reading it. But generally, it could be a fan - created story that involves the relationship or interactions between characters named Urakaka and Deku. It might explore their friendship, adventures together, or even some unique scenarios in the world of the original story they are from.
Well, in such a fanfiction, it often explores a different side of Deku being a villain and his relationship with Todoroki. It could be about how their dynamic changes from the original story. Maybe Deku as a villain has different motives and goals that somehow involve Todoroki, like trying to use Todoroki's power for his own evil plans or trying to turn Todoroki to his side.
The relationship could start with hatred. Bakugou may initially be enraged that Deku has become a villain. But as time passes, he starts to see the reasons behind Deku's transformation, which could lead to a more complex relationship.
In 'deku meets future deku fanfiction', perhaps the future Deku warns the present one about upcoming threats. He could tell him about villains he'll face in the future and how to defeat them. This would give the present Deku an edge in his battles and also in his growth as a hero.
Well, obviously Deku in two forms - the younger and the older version are the main characters. The younger Deku is the one who is still growing and learning, while the older Deku has more experience.
As of now, Deku is very much alive in the manga. The plot hasn't reached a point where he meets such a fate. Usually, main characters like Deku have significant story arcs and aren't easily killed off.