What are the different viewpoints about Ophelia's death? Is her death about revenge? What are the arguments and counterarguments?

Ophelia's death is not an issue of revenge. What is most debated about Ophelia's death is whether it resulted from an accident or was a suicide.

Queen Gertrude is the one who breaks the news of Ophelia's death to the Kingdom, and some interpret her report as the tale of an accidental drowning. Gertrude recounts that Ophelia had been fashioning garlands with leaves of a willow tree and other flowers while sitting on a branch of the willow. "An envious sliver broke," (4.7.173), plummeting Ophelia into the water, where her heavy garments absorbed water, and she was pulled underwater to her death. Gertrude was not present at the time of Ophelia's drowning, however.

A more plausible interpretation is that Ophelia has committed suicide. Earlier in Act 4, Ophelia exhibits symptoms of madness as she wanders aimlessly around Elsinore, singing songs riddled with laments and dark metaphors. She even offers fictitious flowers to Laertes that represent, among other things, loss, duplicity, remembrance, and melancholy. Indeed, the murder of her father, Polonious, at the hands of her lover, Hamlet, has a tremendous impact on Ophelia, and her psyche seems to devolve to the point that she can see no other way out BUT suicide. Her father is dead, her lover now faces almost-certain death, and she faces the loss of her honor.