I thought the jumping back and forward through time did not help the telling of the story if part of the intent is to show how an "ordinary girl" got caught up in a major political scandal.
There are so many people who she met along the way who played a part in how for instance she was ever invited to be at events where politicians etc., were attending.
I am wondering if effectively Stephen Ward was almost like a Jeffrey Epstein in that he used his connections to introduce powerful men to women who were surviving on handouts and favours. Call girls would have had a regular income (even if only a small percentage) of the money they got from clients, which it seems neither CK or MRD had. Having to ask for five bob or whatever.
On another point it is like that Rachman was not the pantomime villan that the tabloids created as much from anti semitism as from fact. And like Stephen Ward and CK and MPD paid the price for the actual sins of the establishment. julesbirch.com/2012/10/24/revealing-the-real-rachman/
I was old enough to remember this story at the time, and the inference was really slight that somehow through "pillow talk" christine keeler could have got information from Profumo to pass to the Russians. Not sure how this series will play it out, but it is as likely that it was a tabloid sting trying to bring down Profumo for political reasons and used the sex orgy angle to discredit him.
When at that time young women who for whatever reason were surviving on their own were extremely vulnerable to sexual exploitation and abuse.
And the male establishment looked after themselves (with their wives turning a blind eye).
(Just as an aside read an article about Jack Monroe staying sober for a year and she talks about celebrities and journalists feeling entitled to grope her in social and work situations 
She seems to be one of those women who spoke of being trans because the femaleness of her body makes her vulnerable)