I did not end up liking how it ended. On one hand it was the creature affirming that despite appearances he was always only himself inside but on the other hand it seemed to resolve some of the existential elements awkwardly - like the whole conflict of the film was just him misunderstanding himself and ended up his uncertainty was just mis-placed.

if you think about the implausibility of the events it just comes across as kind of goofy.

it's likely if you wanted to "deprogram" someone from the influence of a cult leader-like music instructor, surely there were better ways to go besides overdosing the person you wanted to "help" with hallucinogens and getting them to chop off their hand in rural China. Though I went with it since the Allison Williams character was established as being mentally unstable (even though her intentions were good, it was a horrific thing to do to someone you wanted to help). And Logan Browning's character eventually went with the plan since the trauma of her abuse left her mentally unstable as well (even though it didn't manifest itself until after her hand amputation).

One could also question how a prominent music academy could get away with raping it's best students for years. Though the real-life story of long-tern systemic abuse of girls in American gymnastics unfortunately makes this a lot more plausible