Sure is. Deadly Class is based on a comic. The comic provides the foundation for the show's plot, characters, and world-building. However, there are always some differences when adapting from one medium to another.
Yes. The Deadly Class comic came to an end after a fulfilling run. It had a satisfying conclusion that tied up loose ends for the characters and the overall story arc.
Deadly Class isn't based on any particular graphic novel. It's a standalone creation that brings a new and exciting narrative to the world of comics and related media.