I think it's very important to ask a lot of questions throughout your interview day, even if it's something very small or with a quick answer. They seemed to really appreciate and enjoy questions being asked and it shows that you are really excited to be there and to be a part of their program. It also helps them to remember you.
Aside from that, I think your background and patient experience makes you a great applicant and helps you stand out amongst the others. They mentioned in one of my interviews how someone with the bare minimum of requirements but with a lot of volunteer experiences may take a spot over someone with near perfect grades and test scores.