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.
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.
Whip It is purely fictional. It doesn't have its roots in any actual events or people. The story was developed to engage and entertain audiences through a made-up narrative.
Another plot might involve the older Deku being from an alternate timeline. He shows the younger Deku different ways he could have developed his skills and relationships, which makes the younger Deku reevaluate his own path as a hero.
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.
Yes, a wuxia novel with the main character using a whip would recommend "The Fall of Love". The main character, Shen Yishu, was a woman from a brothel. Her martial arts were mainly about whipping, which was also one of the highlights of the novel. In the novel, the description of the whip technique was very vivid and exciting. Basically, all the people who hurt Shen Yishu died under her whip. Her whip skills were once unattainable, so it was really worth reading. I hope you like this fairy's recommendation. Muah ~😗
Naruto's outgoing and boisterous personality would make Deku more confident. He would probably be more upfront and less shy. Naruto's strong sense of justice would also intensify Deku's already existing desire to help others.
Bakugou could use his words. He might tell Deku that he believes in him. For example, he could say 'Deku, you may be a nerd but you're a strong nerd.' It's a backhanded compliment but it shows he has faith in Deku.