Opinion questions are generally the way to go. That way if you end up having multiple people to ask questions of, you may end up with multiple viewpoints! The vet I worked with who did a mock interview with me last year said always always always ask questions in an interview, whether for vet school or a job. The people interviewing you want to know you're interested. You shouldn't be making this sort of big life decision without as much information as you can. She said that in all her years of hiring people, she would never offer jobs to people who didn't ask questions during their interview, because how the heck can you really be seriously interested if you don't want to know more? Whether you agree with that viewpoint or not, the people interviewing you very well might, so better safe than sorry!