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.
The main people behind the Boruto manga are Ukyo Kodachi and Mikio Ikemoto. Their collaboration has resulted in an engaging and popular manga that expands on the Naruto universe.
In Boruto manga, some significant characters have met their demise. The deaths often play a crucial role in driving the plot and adding drama. However, specific names depend on the latest chapters and story arcs.
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.