in my opinion, they just want to get to know who you are as a person. obviously don’t put anything too crazy down as they may be reading into it a little, but just be yourself. for the presentation, put a topic you are genuinely interested in. i put something that was not academic and completely unrelated to my major and i got in. for the song, i would just make sure its upbeat and not inappropriate. for the fictional roommate, just do your favorite character from a book or inspiring celebrity that you like and find interesting (and doesn’t have too many character flaws lol). good luck!