Re Doctor Zhivago PG rating.
I have seen the film MANY years ago so ... but I do remember a rape scene that could justify the rating!
I know it's quite lame for today's society but still ...
And it is a rape, not an abduction like in The Fantasticks!
I have the same feeling with Who Framed Roger Rabbit?
Because it has famous cartoon characters, most think it's a film for children.
I just don't think it is.
I once complained -AND I was a Disney cast member then!!) that this film played continuously, on a somewhat large screen in the Character Shop down at the (then) Disney Village in Florida!
They were promoting the video then, just like they do in stores today.
In that regard, what is the legislation for showing films in stores when some of those films are PG rated because of sex and/or violence?
Nowadays, here, it seems that anything goes! It's just a product I guess! "sell, sell!"
One has to love this consumer's society! 
I forgot about the rape scene in Zhivago. If I remember it was very subtle. I can understand your complaining about Roger Rabbit. Did parents also complain?
Oh, I believe I must have been the only one complaining; I can't tell. They did not give details ...
But ... I thought I might get a "verbal" for doing that, honestly!
They (The Walt Disney World people) might have thought; who's that French guy anyway?!

I like "Roger Rabbit"; the film. I can't stand the character and the voice!
I always thought that the mean character is really evil in that story, and the violence, underlined heavily by the music, really is there!
It sure is not a fairy tale!
And ... there are rumors about a RR prequel, if Spielberg agrees to work with Disney again!