It could also be that Naruto sees in Boruto's eye a sign of an emerging danger. The eye might hold a clue to a new enemy or a brewing conflict. Naruto, being the experienced ninja he is, would then start to take precautions and train Boruto more intensively to face whatever this sign in his eye indicates.
As of now, no. In the Boruto series, their relationship is mainly focused on their friendship and comradeship as ninja. There are some moments that fans might interpret as having a hint of something more, but the story has not made their relationship a romantic one in an official capacity.
Well, it's not necessarily the absolute end. It could be a cliffhanger or a way to create suspense. Sometimes in anime, they say things like this to make the audience think about what might come next. Boruto might face new challenges that are even greater, and this statement is just a pause in the story. For example, there could be a new villain emerging from the shadows, and this 'end' is just the calm before the storm.
The meaning and explanation of the name Li Hongxi was unclear. The search results did not provide a specific explanation or meaning for Li Hongxi's name. Thus, I am unable to give a definite answer.
It could be a lot of things. Maybe it's the backstory of a character. For example, their family history, how they grew up, and what events shaped them into who they are.
It could be a rogue ninja who has a personal vendetta against Boruto's family. This ninja might have caused harm to Boruto's father Naruto in the past, and now Boruto is determined to make him pay.
It could be the Kara organization. They've been shown to be interested in Boruto's Karma mark in the original series, so they might have finally made a move to abduct him in the fanfic.
In a 'naruto dies boruto fanfic', Boruto's character would go through a major transformation. He would be forced to grow up overnight. Initially, he might be consumed by anger and a desire for revenge if Naruto was killed unjustly. But as time passes, he would learn to channel that energy into positive change. He would study his father's leadership style and try to implement it in his own way. He would become more diplomatic, forging alliances with other villages to strengthen Konoha's position. His sense of justice would be refined, and he would be more committed to protecting the world his father loved so much.