What DOES this sentence mean?

Question

One of the faults which I [Shaffer] believe existed in the London version was simply that Salieri has too little to do with Mozart's ruin."
I'm a foreigner.
Please translate literally

I'd like to know..

Answer 1

The London's view of Salieri says he had little to do with the failure of Mozart. When in fact he had everything to do with the fact Mozart failed

Answer 2

Shaffer is saying that in the play he wrote for the London stage, the character of Salieri was not involved enough in the downfall of Mozart. That is why he and Milos Forman revised the script for the movie, to make the story more dramatic. Salieri did exist, but he was not the envious villain the play and, even more so, the movie made him out to be.

Answer 3

The London version was simply that Salieri was not really the cause of Mozart's down fall. Shaffer believes that this is a mistake in the London version.

Meaning that Shaffer believes that Salieri in fact was a (or the) cause of Mozart's down fall.

"I" in this sentence is the speaker, and the speaker is Shaffer.

Answer 4

Shaffer is speaking. He thinks the London version of AMADEUS is not accurate. Shaffer thinks Salieri caused Mozart's downfall.

Answer 5

The writer is describing a London version of the play "Amadeus" or an adaptation from the film of the same name.
In the original, a composer named "Salieri" was so jealous of Mozart's genius that he plotted to destroy the man. In the movie his plot brings about Mozart's fall into alcoholism, madness and finally, death.

The writer is criticizing the London version of the play because he feels it has de-emphasized the role of the principal villain of the story.