I heard Tom Hollander interviewed and he said they went to see loads of CofE vicars and the writers were just lifting stuff from life. Obviously some things are cliches because there's some truth in them.
What's definitely got truth in it is the satanic evo minister - he is, I'm afraid to say, straight from life, I've met those guys, they totally confuse themselves with Jesus and have all sorts of weird sexual repressions going on imho.
And the programme illustrates in broad brush strokes the nightmare of the modern CofE. Fantastic buildings and dwindling congregations except where there's a fab school!
I bet a good proportion of those parents stop going once Johnny and Camilla have got a secure place....