Yes, Boruto is indeed a manga. It expands on the Naruto universe and offers fresh perspectives and storylines. Many fans enjoy reading it to delve deeper into the world created by the series.
No, Boruto is alive in the manga. The plot hasn't led to his death. However, the manga is ongoing, and anything could happen in the later developments.
Naruto would be devastated. He might blame himself for not being able to protect his son. Sasuke would be angry and would likely go on a hunt for the perpetrator. His friends like Sarada and Mitsuki would be heartbroken. Sarada might vow to become stronger to prevent such a tragedy from happening again.
Boruto's reaction would be complex. He'd be heartbroken, for sure. He might start to question his own worth and purpose. But over time, he'd realize that he has to carry on Naruto's legacy. He'd become more serious and focused. He'd also become more empathetic towards others, understanding the weight of sacrifice. He might even start to study Naruto's techniques and leadership style more closely, trying to emulate the things that made Naruto such a great Hokage and hero.