past perfect vs simple past

[Ana laura]

Hello,
I need help with this pairs of sentences:

1- Barry knew it was wrong to steal
2- Barry knew it had been wrong to steal

3- Sally never saw the film
4- sally had never seen the film before

please tell me if this answers are ok:

3-means she never saw the film?
4- means sally hadn't seen the film until some day she saw it?
I am really confused with number 1 and 2.

[Tdol]

1- We don't know whether he stole anything.
2- He stole, but was aware that it was wrong
3- She didn't see it and it is longer in the cinemas, etc
4- She has seen the film now, but it was her first time- it's probably one of those fiolms that everyone else has seen many times, but she had missed it when it came out.