Are crazy people more creative than sane ones?

serial killers are a good example and deserve some respect

Not exactly.
Creative people are less tied to some social adaptative prejudices and filters.
And this is shared with some pathological typologies.
Not necessarily causal related, but a side facet, anyhow.

Ah, Yeah! Cut and ear off, or go nuts and your art and works triple in price!

I think some people can channel their emotions better than others can.