These are pretty straight forward questions. Not really tricky. They have right and wrong answers (multiple of each) and do not particularly depend on who is interviewing you. I have answered all of these at least once on the interview trail, or a similarly worded question...
1. If you had the choice of giving a transplant to an elderly woman with various health problems or a 20-year-old drug addict, how and who do you choose? Why?
Purpose: Attempt to trap applicant into comparing elderly vs. young + drug addict. Hard route - picking one and justifying. Easier and generally more fluid - Redirect. Convince the interviewer that the question is invalid, stupid, moot, take your pick.
Personal take: I would attack the simplicity of the descriptions of the patients. No person can be or should be simplified down into "elderly female" or "drug addict". In each of those groups there is a huge variation.
2. What is your "cause/purpose"?
Purpose: Sell yourself. Can also be translated into, "Why should I invest resources in training you?" Or, "Medical training is long and hard. What makes you wake up every day and strive to achieve X, Y and Z?" This is probably the fairest question an interviewer can ask. It is the simplest, most direct and probably one of the most useful questions. If you do not get this while interviewing for medical school, you WILL get it interviewing for residency. Of the 18 programs I interviewed at this Spring, I was asked at 10+ some derivative of this question.
Personal take: You can not fake this question. It is obvious and transparent if you do. When you put a person's answer in the context of their application you can easily derive the sincerity of all the other answers that an applicant gives. It all comes down to having a theme to your application. Activities complimenting a personal statement which in term is reflected in your answer to this question. An ego helps when answering this question as long as it doesn't get out of hand.
3. Rank intelligence, compassion, and integrity in the order of importance to you.
Purpose: Nobody actually cares how you rank these. None are less important than the others. The trap is diminishing the importance of any of them. You should be able to answer the question, "Why is _________ important to the practice of medicine?" Where the blank is filled with intelligence, compassion or integrity. You should also have a specific example or two for each. You can make some arbitrary order if you choose, but in the end you can't order these entities.
Personal take: I would never provide the evidence unless provoked by this type of question, but I can and have easily provided examples for interviewers of how I exemplify each of those. Again, goes along with being able to sell yourself. You have to be able to self promote when asked to.
4. If you had a magic pen, what would you do to remedy health care in America?
Purpose: Translation: "How close do you follow the political atmosphere and the world outside of your little bubble?" There are a lot of ways to answer this. The way you shoot yourself in the foot is going for too much. The second part of that is that you need to be humble when answering. If American health care could be solved that easily, it would have been done. Pick a pet issue, promoting preventative medicine, mandating standardization of EMRs, etc. And propose a solution. Do not try to fix the entire country.
5. I am a dying patient, and you are my doctor. Tell me that I am going to die.
Purpose: Weed out the sociopaths. Do not tell people you know how they are feeling. You don't. Even if you have a closely related experience, you don't know how they are feeling/responding. Do not use words like expire, pass away etc. They are going to die. That has to be crystal clear and up front. What comes after is the important part. Offer support, personal and then in the form of palliative care/hospice as well as grief counseling.
Personal take: I told a 25 year old that they were going to likely die in the next 2-3 months last week. I have told 10+ patients that they are going to lose anywhere from a toe to 50%+ of their leg in the last 6 weeks. The formula for dealing with these issues is among the simplest out there. The hard part is actually seeing someone who is actually going to be in a body bag in a couple months and being able to follow through. As an interview question this is fairly straight forward.
6. Do you think health care is a right or a privilege?
Purpose: Weed out people who have never thought about the question. This is an easy question to answer. Both are easily justifiable. You can easily flip-flop in your opinion between interviews. Which side you fall on does not matter. Having a reasonably thought out answer as well as counters to the basic counter arguments is what is required.