Sasuke often appears in different story arcs of the Boruto manga, depending on the current plot and mission. Sometimes he's on a solo mission, sometimes he's involved in events related to the village.
Yes. The English dub for BlazBlue Central Fiction exists. It adds to the accessibility and appeal of the game for English-speaking players, allowing them to immerse themselves in the story and gameplay with familiar language.
Naruto is likely to be popular too. Even though it's a Boruto x Sasuke fanfic, Naruto's relationship with both of them is so important. He could play a role in supporting them from the sidelines or even getting involved in a crucial part of the story.
Sasuke's reaction could be complex. At first, he would be enraged. After all, the Rinnegan is a symbol of his power and his journey to gain strength. However, he might also have some mixed feelings. He and Naruto have a deep bond, and he might wonder if Naruto had a good reason for taking it. But overall, his initial reaction would likely be one of fury and a desire to get his power back.