There probably is. Fanfiction writers often come up with really creative crossovers. However, the quality can vary a great deal. Some might be really well - written with interesting plotlines that blend the Naruto and Soul Eater universes in a unique way, while others might not be as good. It's all about exploring different interpretations of the characters and their worlds.
I think it is. The plot has depth, the action scenes are exciting, and it has a good mix of humor and drama. However, it might not be for everyone depending on personal preferences.
Black Star would probably see Asura as a new opponent to prove his strength against. He would be eager to fight, shouting his usual boasts about being the one to defeat the most powerful foe. However, he might quickly realize that Asura is on a whole different level and would need to rely on his friends more than he thought.
The Soul Eater manga did end. It wrapped up its plotlines and gave a satisfying conclusion to the fans. However, opinions on the ending may vary among readers.