My DH is an academic at one of these universities. He is not at all scary. He is actually quite nice and reasonable. Every year he interviews about 60 potential candidates for his college, and subject. He sometimes interviews as a second interviewer for other subjects and other colleges(they need to double up to protect themselves from some of the compliants I have heard about when they reject people). I know someone who went into an interview and the door handle fell off. the candidate thought it was deliberate. It wasn't it just fell off. When academics interview that many people they do not have the time to come up with trick questions and scenarios. There is nothing in it for them or the candidate so they don't do it!
He does not ask about Ford. He asks fairly sensible and wide ranging questions about the subject (which in his case he does not need people to have studied before). He wants to see if applicants can think for themselves, and follow a line of argument through. He sometimes makes the subjects he asks about political, sometimes quirky he doesn't care what people say he just wants to know whether they can think and justify what they say. He has a world view but he only care if others can justify what they think not what he does.
Before the interview he reads the application forms. He highlights some bits mainly to give him ideas about what to talk about for 20 minutes. If a candidate has said that they have read his book he ignores it. If they mention another book he will usually ask about it to see what they thought (and or check they are telling the truth). He does look at grades at GCSE and A level, and particularly modules If the candidates have As and A*s that will usually do him and not be enough to differentiate in the same way as an interview. If they have some Bs he is happy with that too. they are on small part of the picture (albeit an important one)
His college usually has a high number of applicants to places. He regularly goes to the pool though if he does not think the applicants are of a high enough standard.
He really does not care whether students did D of E, play sport, play a musical instrument, etc. I think that last point is the main difference between oxford, cambridge and everywhere else.
When students are accepted to colleges can be high pressure. My course back in the early 90s had a lot my content than other universities did. Many more lectures and tutorials. But it also had a lot more support, financial and emotional.
My DH is a pastoral tutor. In the last few years he has visitied students in hospitals, he has arranged counselling for students, he has tracked down funds for students, he has broken up parties and done countless more things besides. He listened to students and talked them through exam and other worries at the time his step father was diagnosed with a terminal illness and just wanted to tell them it wasn't that important. Ditto when I had a miscarriage. Ditto when our son was in hospital. He remembers what its like when it feels like the only thing that matters were the grades. Sometimes he even tells students what grades he got in the 80s (which were not all firsts)
As I said he is not scary and if students get in, and they chose to access it the support is wonderful. But like all places there are some people you like, and some you don't. They are some good influences and some bad. Personally I know fair more hooray henrys and people who went to private schools through my work than I ever met at my college.