>What is a historical fact is that Salieri openly and explicitly prevented Mozart's career from going where Mozart wanted it to go.

Quotes from credible modern historians please. To my knowledge most historians think that there is no concrete evidence of this. There was just competition for jobs. Rest is drama added later.

>Whether or not he actually killed Mozart we can never truly know.

Good example of the false rumor. Salieri seems to even have confessed the murder when he was delirious but nobody believed him even then. Later he took that confession back.